Merge branch 'develop' into vvysokikh/fix-check-zero-checkid

.clang-tidy

@@ -9,48 +9,101 @@ Checks: "-*,
 
   cppcoreguidelines-*,
   -cppcoreguidelines-avoid-c-arrays,
+  -cppcoreguidelines-avoid-capturing-lambda-coroutines,
   -cppcoreguidelines-avoid-const-or-ref-data-members,
   -cppcoreguidelines-avoid-do-while,
+  -cppcoreguidelines-avoid-goto,
   -cppcoreguidelines-avoid-magic-numbers,
   -cppcoreguidelines-avoid-non-const-global-variables,
+  -cppcoreguidelines-avoid-reference-coroutine-parameters,
   -cppcoreguidelines-c-copy-assignment-signature,
+  -cppcoreguidelines-explicit-virtual-functions,
   -cppcoreguidelines-interfaces-global-init,
+  -cppcoreguidelines-macro-to-enum,
   -cppcoreguidelines-macro-usage,
   -cppcoreguidelines-missing-std-forward,
   -cppcoreguidelines-narrowing-conversions,
+  -cppcoreguidelines-no-malloc,
+  -cppcoreguidelines-noexcept-destructor,
   -cppcoreguidelines-noexcept-move-operations,
+  -cppcoreguidelines-noexcept-swap,
   -cppcoreguidelines-non-private-member-variables-in-classes,
   -cppcoreguidelines-owning-memory,
+  -cppcoreguidelines-prefer-member-initializer,
   -cppcoreguidelines-pro-bounds-array-to-pointer-decay,
   -cppcoreguidelines-pro-bounds-avoid-unchecked-container-access,
   -cppcoreguidelines-pro-bounds-constant-array-index,
   -cppcoreguidelines-pro-bounds-pointer-arithmetic,
+  -cppcoreguidelines-pro-type-const-cast,
+  -cppcoreguidelines-pro-type-cstyle-cast,
   -cppcoreguidelines-pro-type-reinterpret-cast,
   -cppcoreguidelines-pro-type-union-access,
+  -cppcoreguidelines-pro-type-vararg,
+  -cppcoreguidelines-slicing,
   -cppcoreguidelines-special-member-functions,
 
   llvm-namespace-comment,
 
   misc-*,
+  -misc-anonymous-namespace-in-header,
+  -misc-confusable-identifiers,
+  -misc-coroutine-hostile-raii,
+  -misc-misleading-bidirectional,
+  -misc-misleading-identifier,
   -misc-multiple-inheritance,
+  -misc-new-delete-overloads,
   -misc-no-recursion,
+  -misc-non-copyable-objects,
   -misc-non-private-member-variables-in-classes,
   -misc-override-with-different-visibility,
+  -misc-predictable-rand,
+  -misc-unconventional-assign-operator,
+  -misc-uniqueptr-reset-release,
   -misc-unused-parameters,
   -misc-use-anonymous-namespace,
   -misc-use-internal-linkage,
 
   modernize-*,
+  -modernize-avoid-bind,
   -modernize-avoid-c-arrays,
   -modernize-avoid-c-style-cast,
+  -modernize-avoid-setjmp-longjmp,
+  -modernize-avoid-variadic-functions,
+  -modernize-deprecated-ios-base-aliases,
+  -modernize-loop-convert,
+  -modernize-macro-to-enum,
+  -modernize-min-max-use-initializer-list,
+  -modernize-raw-string-literal,
+  -modernize-redundant-void-arg,
+  -modernize-replace-auto-ptr,
+  -modernize-replace-disallow-copy-and-assign-macro,
+  -modernize-replace-random-shuffle,
   -modernize-return-braced-init-list,
+  -modernize-shrink-to-fit,
+  -modernize-unary-static-assert,
+  -modernize-use-auto,
+  -modernize-use-bool-literals,
+  -modernize-use-constraints,
+  -modernize-use-default-member-init,
   -modernize-use-integer-sign-comparison,
+  -modernize-use-noexcept,
+  -modernize-use-nullptr,
+  -modernize-use-std-format,
+  -modernize-use-std-print,
   -modernize-use-trailing-return-type,
+  -modernize-use-transparent-functors,
+  -modernize-use-uncaught-exceptions,
 
   performance-*,
   -performance-avoid-endl,
   -performance-enum-size,
+  -performance-inefficient-algorithm,
+  -performance-inefficient-string-concatenation,
+  -performance-no-int-to-ptr,
+  -performance-noexcept-destructor,
   -performance-noexcept-move-constructor,
+  -performance-noexcept-swap,
+  -performance-type-promotion-in-math-fn,
   -performance-unnecessary-copy-initialization,
   -performance-unnecessary-value-param,
 

.envrc

@@ -1 +0,0 @@
-use flake

.github/scripts/levelization/results/ordering.txt

@@ -72,6 +72,7 @@ test.app > xrpl.server
 test.app > xrpl.shamap
 test.app > xrpl.tx
 test.basics > test.jtx
+test.basics > test.unit_test
 test.basics > xrpl.basics
 test.basics > xrpl.core
 test.basics > xrpld.rpc
@@ -161,6 +162,9 @@ test.protocol > test.unit_test
 test.protocol > xrpl.basics
 test.protocol > xrpl.json
 test.protocol > xrpl.protocol
+test.resource > test.unit_test
+test.resource > xrpl.basics
+test.resource > xrpl.resource
 test.rpc > test.jtx
 test.rpc > xrpl.basics
 test.rpc > xrpl.config
@@ -184,6 +188,12 @@ test.server > xrpld.core
 test.server > xrpl.json
 test.server > xrpl.protocol
 test.server > xrpl.server
+test.shamap > test.unit_test
+test.shamap > xrpl.basics
+test.shamap > xrpl.config
+test.shamap > xrpl.nodestore
+test.shamap > xrpl.protocol
+test.shamap > xrpl.shamap
 test.unit_test > xrpl.basics
 test.unit_test > xrpl.protocol
 tests.libxrpl > xrpl.basics
@@ -195,7 +205,6 @@ tests.libxrpl > xrpl.net
 tests.libxrpl > xrpl.nodestore
 tests.libxrpl > xrpl.protocol
 tests.libxrpl > xrpl.protocol_autogen
-tests.libxrpl > xrpl.resource
 tests.libxrpl > xrpl.server
 tests.libxrpl > xrpl.shamap
 tests.libxrpl > xrpl.tx

.github/workflows/reusable-build-test-config.yml

@@ -227,8 +227,7 @@ jobs:
               --build . \
               --config "${BUILD_TYPE}" \
               --parallel "${BUILD_NPROC}" \
-              --target "${CMAKE_TARGET}" \
-              2>&1 | tee build.log
+              --target "${CMAKE_TARGET}"
 
       - name: Show ccache statistics
         if: ${{ inputs.ccache_enabled }}
@@ -326,7 +325,7 @@ jobs:
           LD_PRELOAD="$PRELOAD" ./xrpld --unittest --unittest-jobs "${BUILD_NPROC}" 2>&1 | tee unittest.log
 
       - name: Show test failure summary
-        if: ${{ failure() }}
+        if: ${{ failure() && !inputs.build_only }}
         env:
           WORKING_DIR: ${{ runner.os == 'Windows' && format('{0}\{1}', env.BUILD_DIR, inputs.build_type) || env.BUILD_DIR }}
         run: |
@@ -337,16 +336,13 @@ jobs:
 
           cd "${WORKING_DIR}"
 
-          if [ -f unittest.log ]; then
-              if ! grep -E "failed" unittest.log | grep -vE "^I[0-9]|^[0-9]+> (ERR:|FTL:)"; then
-                  echo "unittest.log present but no failure lines found."
-              fi
-          elif [ -f build.log ]; then
-              if ! grep -E "error:" build.log; then
-                  echo "build.log present but no compile errors found."
-              fi
-          else
-              echo "unittest.log/build.log not found; something went wrong."
+          if [ ! -f unittest.log ]; then
+              echo "unittest.log not found; embedded tests may not have run."
+              exit 0
+          fi
+
+          if ! grep -E "failed" unittest.log; then
+              echo "Log present but no failure lines found in unittest.log."
           fi
       - name: Debug failure (Linux)
         if: ${{ failure() && runner.os == 'Linux' && !inputs.build_only }}

.pre-commit-config.yaml

@@ -43,11 +43,6 @@ repos:
         language: python
         entry: ./bin/pre-commit/fix_pragma_once.py
         files: \.(h|hpp)$
-      - id: check-doxygen-style
-        name: check Doxygen comment style
-        entry: ./bin/pre-commit/check_doxygen_style.py
-        language: python
-        types_or: [c++, c]
 
   - repo: https://github.com/pre-commit/mirrors-clang-format
     rev: dd18dad857d6133e90bbe478f4f2f22ec0030269 # frozen: v22.1.5
@@ -95,19 +90,20 @@ repos:
   - repo: https://github.com/streetsidesoftware/cspell-cli
     rev: ea11f9efc0bec520073405bc30552da887ba71bc # frozen: v10.0.1
     hooks:
-      - id: cspell
-        name: check changed files spelling
+      - id: cspell # Spell check changed files
         exclude: |
           (?x)^(
-              \.cspell\.config\.yaml|
+              .config/cspell.config.yaml|
               include/xrpl/protocol_autogen/(transactions|ledger_entries)/.*
           )$
-      - id: cspell
+      - id: cspell # Spell check the commit message
         name: check commit message spelling
         args:
           - --no-must-find-files
           - --no-progress
           - --no-summary
+          - --files
+          - .git/COMMIT_EDITMSG
         stages: [commit-msg]
 
   - repo: local

BUILD.md

@@ -25,7 +25,7 @@ You can verify that the required tools are installed and runnable with:
 | ----------- | --------------- |
 | GCC         | 15.2            |
 | Clang       | 22              |
-| Apple Clang | 21              |
+| Apple Clang | 17              |
 | MSVC        | 19.44[^windows] |
 
 ## Operating Systems

bin/pre-commit/check_doxygen_style.py

@@ -1,440 +0,0 @@
-#!/usr/bin/env python3
-"""
-Check C++ Doxygen comment style.
-
-Enforces the house convention for documentation comments:
-
-  * Use ``/** ... */`` blocks, not ``///``, ``//!`` or ``/*! ... */``; a plain
-    ``/* ... */`` that contains Doxygen commands is a doc comment missing its
-    second star. Trailing member-after comments use ``///<`` (not ``//!<``,
-    ``/*!< ... */`` or ``/**< ... */`` -- the block forms get reflowed and
-    mis-attached by clang-format on packed enum values, the line form does not).
-  * ``/**`` sits alone on its line; the closing ``*/`` sits alone on its line.
-  * Every content line is prefixed with `` * `` (no bare-indented continuation).
-  * The first content line is flush (not over-indented).
-  * Doxygen commands use the ``@cmd`` form, not ``\\cmd``.
-  * Use ``@return`` / ``@throws`` rather than prose ``Returns:`` / ``Throws:``.
-  * A plain ``//`` comment carrying a block-level ``@command`` (``@param``,
-    ``@return``, ``@see``, ...) is documentation and must be a ``/** ... */``
-    block (Doxygen ignores ``//``).
-  * Use canonical command spellings: ``@return`` (not ``@returns``),
-    ``@throws`` (not ``@throw``), ``@see`` (not ``@sa``).
-  * Order block tags ``@tparam`` -> ``@param`` -> ``@return``. (Whether
-    ``@param`` order matches the signature is not checked here -- too fragile to
-    parse; Doxygen's WARN_IF_DOC_ERROR covers name mismatches.)
-  * One-liners are expanded to three lines, EXCEPT bare markers ``@{`` / ``@}``
-    / ``@cond [label]`` / ``@endcond`` / ``@file [name]`` which stay on one line.
-
-Left intentionally alone (recognized, valid Doxygen that is not this style's
-concern):
-
-  * ``///<`` trailing "member-after" comments (the house form).
-  * Divider lines made only of slashes (``//////////``).
-  * Plain ``/* ... */`` (non-Doxygen) comments.
-
-Usage:
-    check_doxygen_style.py [FILE ...]      # explicit files
-    check_doxygen_style.py                 # default: src/ and include/ trees
-
-Exit status is non-zero if any violation is found.
-"""
-
-import argparse
-import re
-import sys
-from collections.abc import Iterable, Iterator
-from dataclasses import dataclass
-from enum import Enum
-from pathlib import Path
-
-
-class Category(Enum):
-    """A kind of style violation: a printed ``label`` and its ``description``.
-
-    The description is the default message; a few categories whose wording
-    depends on the offending text (see ``Finding.detail``) override it.
-    """
-
-    def __init__(self, label: str, description: str) -> None:
-        self.label = label
-        self.description = description
-
-    BACKSLASH_COMMAND = ("backslash-command", "use the @cmd form, not \\cmd")
-    WRONG_COMMAND = ("wrong-command", "use the canonical command spelling")
-    TRIPLE_SLASH = ("triple-slash", "use a /** ... */ block instead of ///")
-    QT_MEMBER = ("qt-member", "use ///< instead of //!<")
-    QT_LINE = ("qt-line", "use a /** ... */ block instead of //!")
-    BLOCK_MEMBER = ("block-member", "use ///< instead of /**<")
-    QT_BLOCK_MEMBER = ("qt-block-member", "use ///< instead of /*!<")
-    DOC_IN_LINE_COMMENT = (
-        "doc-in-line-comment",
-        "use a /** ... */ block for documentation, not //",
-    )
-    QT_COMMENT = ("qt-comment", "use /** instead of /*!")
-    SINGLE_LINE_BLOCK = (
-        "single-line-block",
-        "expand one-line /** ... */ to a multi-line block "
-        "(markers @{ @} @cond @endcond @file may stay)",
-    )
-    TEXT_ON_OPENER = ("text-on-opener", "move text off the /** opener line")
-    BARE_CONTINUATION = ("bare-continuation", 'prefix continuation lines with " * "')
-    OVER_INDENTED = ("over-indented", "first content line is over-indented")
-    OVER_INDENTED_TAG = (
-        "over-indented-tag",
-        'Doxygen tag over-indented; use a single space after "*"',
-    )
-    COMBINED_MARKER = (
-        "combined-marker",
-        "scope marker @{ / @} should be its own single-line /** @{ */ block",
-    )
-    PROSE_LABEL = ("prose-label", "use a Doxygen tag instead of a prose label")
-    CONTENT_ON_CLOSER = ("content-on-closer", "move content off the closing */ line")
-    PLAIN_BLOCK_DOC = (
-        "plain-block-doc",
-        "documentation comment must open with /** not /*",
-    )
-    TAG_ORDER = (
-        "tag-order",
-        "block tags out of order; expected @tparam, then @param, then @return",
-    )
-
-
-@dataclass(frozen=True)
-class Finding:
-    """A single style violation at a 1-based line number.
-
-    ``detail`` overrides the category's default description when the message
-    depends on the offending text (e.g. which command was misspelled).
-    """
-
-    line: int
-    category: Category
-    detail: str | None = None
-
-    @property
-    def message(self) -> str:
-        return self.detail if self.detail is not None else self.category.description
-
-
-DEFAULT_ROOTS = ("src", "include")
-EXTS = {".h", ".hpp", ".cpp", ".ipp", ".cxx", ".cc"}
-
-# Every Doxygen command we recognize when written with a backslash (\cmd).
-_ALL_COMMANDS = (
-    "brief|param|tparam|return|returns|retval|note|warning|pre|post|see|sa|ref|"
-    "throw|throws|exception|deprecated|details|code|endcode|verbatim|endverbatim|"
-    "li|arg|c|internal|since|todo|attention|remark|remarks|ingroup|defgroup"
-)
-# Block-level tags whose over-indentation we flag inside a block body.
-_BLOCK_TAGS = (
-    "param|tparam|returns?|retval|brief|throws?|note|warning|"
-    "pre|post|see|sa|details|deprecated"
-)
-# Tags that, appearing anywhere in a comment, mark it as documentation.
-_ANY_DOC_TAGS = (
-    "param|tparam|returns?|retval|brief|throws?|note|warning|pre|post|see|sa"
-)
-# Tags that make a plain // comment a mis-styled doc comment.
-_LINE_DOC_TAGS = "brief|param|tparam|returns?|retval|throws?|note|see|pre|post"
-
-# \cmd that should be @cmd.
-RE_BACKSLASH_CMD = re.compile(r"\\(" + _ALL_COMMANDS + r")\b")
-# Bare markers that may legitimately stay on a single line.
-RE_MARKER = re.compile(r"^@(\{|\}|cond(\s.*)?|endcond|file(\s.*)?)$")
-# Prose section labels that should be Doxygen tags.
-RE_PROSE_LABEL = re.compile(r"^\*\s(Returns|Throws|Exceptions):\s*$")
-# An over-indented block tag: "*" followed by 2+ spaces then the tag.
-RE_OVERINDENTED_TAG = re.compile(r"^\*\s{2,}@(" + _BLOCK_TAGS + r")\b")
-# Any documentation tag (used to spot a doc comment hiding in a plain /* */).
-RE_ANY_DOC_TAG = re.compile(r"@(" + _ANY_DOC_TAGS + r")\b")
-# A documentation tag inside a // comment.
-RE_LINE_DOC_TAG = re.compile(r"@(" + _LINE_DOC_TAGS + r")\b")
-# Order-relevant tags, for the @tparam -> @param -> @return ordering check.
-RE_ORDER_TAG = re.compile(r"^\*\s*@(param|tparam|returns?|retval)\b")
-# First content line indented by 2+ spaces after the "*".
-RE_FIRST_OVERINDENT = re.compile(r"^\s*\*\s{2,}\S")
-# A scope marker @{ / @} sharing a comment with other text.
-RE_COMBINED_MARKER = re.compile(r"^\*\s*@[{}]\s*$")
-
-# Non-canonical command spellings -> the house spelling (bare command names).
-# Used both to flag a wrong @form and to suggest the right @form for a \wrong.
-CANONICAL_COMMAND = {"returns": "return", "throw": "throws", "sa": "see"}
-WRONG_SPELLINGS = [
-    (re.compile(rf"@{wrong}\b"), f"@{right}")
-    for wrong, right in CANONICAL_COMMAND.items()
-]
-
-# Order block tags should appear in; a body out of this order is a violation.
-EXPECTED_TAG_ORDER = ("tparam", "param", "return")
-
-
-def is_doxy_open(stripped: str) -> bool:
-    """True for a line-start Doxygen block opener we should normalize."""
-    if stripped.startswith("/*!"):  # Qt-style Doxygen
-        return not stripped.startswith("/*!<")  # member-after, leave inline
-    return (
-        stripped.startswith("/**")
-        and not stripped.startswith("/***")
-        and not stripped.startswith("/**/")
-        and not stripped.startswith("/**<")
-    )
-
-
-def _flag_commands(raw_line: str, stripped: str, index: int) -> list[Finding]:
-    """Flag \\cmd and misspelled @cmd on a comment line (opener, body, or closer)."""
-    if not stripped.startswith(("*", "//", "/*")):
-        return []
-    findings: list[Finding] = []
-    backslash = RE_BACKSLASH_CMD.search(raw_line)
-    if backslash:
-        command = backslash.group(1)
-        canonical = CANONICAL_COMMAND.get(command, command)
-        findings.append(
-            Finding(
-                index + 1,
-                Category.BACKSLASH_COMMAND,
-                f"use @{canonical} instead of \\{command}",
-            )
-        )
-    for pattern, replacement in WRONG_SPELLINGS:
-        wrong = pattern.search(raw_line)
-        if wrong:
-            findings.append(
-                Finding(
-                    index + 1,
-                    Category.WRONG_COMMAND,
-                    f"use {replacement} instead of {wrong.group(0)}",
-                )
-            )
-    return findings
-
-
-def _flag_line_comment(raw_line: str, stripped: str, index: int) -> Finding | None:
-    """Return the finding for a single-line comment form (///, //!, /**<, ...), else None."""
-    if stripped.startswith("///") and not stripped.startswith(("////", "///<")):
-        return Finding(index + 1, Category.TRIPLE_SLASH)
-    if "//!<" in raw_line:
-        return Finding(index + 1, Category.QT_MEMBER)
-    if stripped.startswith("//!"):
-        return Finding(index + 1, Category.QT_LINE)
-    if "/**<" in raw_line:
-        return Finding(index + 1, Category.BLOCK_MEMBER)
-    if "/*!<" in raw_line:
-        return Finding(index + 1, Category.QT_BLOCK_MEMBER)
-    if stripped.startswith("//") and RE_LINE_DOC_TAG.search(stripped):
-        return Finding(index + 1, Category.DOC_IN_LINE_COMMENT)
-    return None
-
-
-def _flag_single_line_block(stripped: str, line_no: int, is_qt: bool) -> list[Finding]:
-    """Findings for a whole /** ... */ or /*! ... */ block on one line."""
-    inner = re.sub(r"^/\*[*!]", "", stripped)
-    inner = re.sub(r"\*/\s*$", "", inner).strip()
-    findings: list[Finding] = []
-    if is_qt:
-        findings.append(Finding(line_no, Category.QT_COMMENT))
-    if inner and not RE_MARKER.match(inner):
-        findings.append(Finding(line_no, Category.SINGLE_LINE_BLOCK))
-    return findings
-
-
-def _canonical_order_tag(body: str) -> str | None:
-    """The order-relevant tag (tparam/param/return) a body line opens with, if any."""
-    match = RE_ORDER_TAG.match(body)
-    if match is None:
-        return None
-    command = match.group(1)
-    return "return" if command in ("return", "returns", "retval") else command
-
-
-def _flag_body_line(
-    body_line: str, line_no: int, is_first_content: bool
-) -> list[Finding]:
-    """Findings for one interior line of a multi-line block."""
-    body = body_line.strip()
-    findings: list[Finding] = []
-    if body and not body.startswith("*"):
-        findings.append(Finding(line_no, Category.BARE_CONTINUATION))
-    if body.startswith("*"):
-        if is_first_content and RE_FIRST_OVERINDENT.match(body_line):
-            findings.append(Finding(line_no, Category.OVER_INDENTED))
-        if RE_OVERINDENTED_TAG.match(body):
-            findings.append(Finding(line_no, Category.OVER_INDENTED_TAG))
-        if RE_COMBINED_MARKER.match(body):
-            findings.append(Finding(line_no, Category.COMBINED_MARKER))
-        label = RE_PROSE_LABEL.match(body)
-        if label:
-            suggested_tag = "@return" if label.group(1) == "Returns" else "@throws"
-            findings.append(
-                Finding(
-                    line_no,
-                    Category.PROSE_LABEL,
-                    f'use {suggested_tag} instead of prose "{label.group(1)}:"',
-                )
-            )
-    return findings
-
-
-def _flag_closer(closer_line: str, line_no: int) -> list[Finding]:
-    """Findings for content sharing the closing */ line."""
-    before = closer_line[: closer_line.index("*/")].strip()
-    if before and before != "*":
-        return [Finding(line_no, Category.CONTENT_ON_CLOSER)]
-    return []
-
-
-def _flag_tag_order(first_tag_line: dict[str, int]) -> list[Finding]:
-    """One finding if the present block tags are not in EXPECTED_TAG_ORDER."""
-    tag_lines = [
-        first_tag_line[tag] for tag in EXPECTED_TAG_ORDER if tag in first_tag_line
-    ]
-    if tag_lines != sorted(tag_lines):
-        return [Finding(min(tag_lines), Category.TAG_ORDER)]
-    return []
-
-
-def _flag_doxy_block(lines: list[str], start: int) -> tuple[int, list[Finding]]:
-    """Handle a /** or /*! block opening at ``start``; return (next index, findings)."""
-    raw_line = lines[start]
-    stripped = raw_line.lstrip()
-    open_pos = raw_line.index("/*")
-    is_qt = stripped.startswith("/*!")
-
-    # A whole block on one line: /** ... */.
-    if "*/" in raw_line[open_pos + 2 :]:
-        return start + 1, _flag_single_line_block(stripped, start + 1, is_qt)
-
-    # Multi-line block: opener, then scan the body to the closer.
-    findings: list[Finding] = []
-    if is_qt:
-        findings.append(Finding(start + 1, Category.QT_COMMENT))
-    if raw_line[open_pos + 3 :].strip():
-        findings.append(Finding(start + 1, Category.TEXT_ON_OPENER))
-
-    line_count = len(lines)
-    cursor = start + 1
-    is_first_content = True
-    first_tag_line: dict[str, int] = {}  # canonical tag -> 1-based first line
-    while cursor < line_count and "*/" not in lines[cursor]:
-        body_line = lines[cursor]
-        body = body_line.strip()
-        findings.extend(_flag_commands(body_line, body, cursor))
-        tag = _canonical_order_tag(body)
-        if tag is not None:
-            first_tag_line.setdefault(tag, cursor + 1)
-        findings.extend(_flag_body_line(body_line, cursor + 1, is_first_content))
-        if body.startswith("*"):
-            is_first_content = False
-        cursor += 1
-
-    if cursor < line_count:
-        closer_line = lines[cursor]
-        findings.extend(_flag_commands(closer_line, closer_line.strip(), cursor))
-        findings.extend(_flag_closer(closer_line, cursor + 1))
-    findings.extend(_flag_tag_order(first_tag_line))
-
-    return cursor + 1, findings
-
-
-def _flag_plain_block(lines: list[str], start: int) -> tuple[int, list[Finding]]:
-    """Handle a line-start plain /* ... */ block; return (next index, findings).
-
-    Only flagged when it hides a documentation command (a missing second star).
-    """
-    line_count = len(lines)
-    cursor = start
-    while cursor < line_count and "*/" not in lines[cursor]:
-        cursor += 1
-    findings: list[Finding] = []
-    # The opener (start) is command-checked by check_file; check the rest here.
-    for i in range(start + 1, min(cursor + 1, line_count)):
-        findings.extend(_flag_commands(lines[i], lines[i].strip(), i))
-    block_text = "\n".join(
-        lines[start : cursor + 1] if cursor < line_count else lines[start:]
-    )
-    if RE_ANY_DOC_TAG.search(block_text):
-        findings.append(Finding(start + 1, Category.PLAIN_BLOCK_DOC))
-    next_index = cursor + 1 if cursor < line_count else line_count
-    return next_index, findings
-
-
-def check_source(text: str) -> list[Finding]:
-    """Return all style violations found in the given source text."""
-    lines = text.split("\n")
-    findings: list[Finding] = []
-    line_count = len(lines)
-    index = 0
-    in_plain_block = False  # inside a mid-line, non-Doxygen /* ... */
-    while index < line_count:
-        raw_line = lines[index]
-        stripped = raw_line.lstrip()
-
-        # Skip the interior of a plain block opened on an earlier line.
-        if in_plain_block:
-            in_plain_block = "*/" not in raw_line
-            index += 1
-            continue
-
-        findings.extend(_flag_commands(raw_line, stripped, index))
-
-        line_finding = _flag_line_comment(raw_line, stripped, index)
-        if line_finding is not None:
-            findings.append(line_finding)
-            index += 1
-        elif is_doxy_open(stripped):
-            index, block_findings = _flag_doxy_block(lines, index)
-            findings.extend(block_findings)
-        elif stripped.startswith("/*"):
-            index, block_findings = _flag_plain_block(lines, index)
-            findings.extend(block_findings)
-        else:
-            # A /* that opens mid-line without closing starts a plain block.
-            if "/*" in raw_line and not stripped.startswith("//"):
-                if "*/" not in raw_line[raw_line.index("/*") + 2 :]:
-                    in_plain_block = True
-            index += 1
-    return findings
-
-
-def check_file(path: Path) -> list[Finding]:
-    """Return all style violations found in one file."""
-    return check_source(path.read_text(encoding="utf-8"))
-
-
-def iter_files(paths: Iterable[str]) -> Iterator[Path]:
-    """Yield every C++ source file among the given files and directories."""
-    for raw_path in paths:
-        path = Path(raw_path)
-        if path.is_dir():
-            for candidate in path.rglob("*"):
-                if candidate.is_file() and candidate.suffix in EXTS:
-                    yield candidate
-        elif path.suffix in EXTS:
-            yield path
-
-
-def main() -> int:
-    parser = argparse.ArgumentParser(description="Check Doxygen comment style.")
-    parser.add_argument(
-        "files", nargs="*", help="files or directories (default: src/ include/)"
-    )
-    parser.add_argument(
-        "-q", "--quiet", action="store_true", help="only print the summary count"
-    )
-    args = parser.parse_args()
-    roots = args.files or [root for root in DEFAULT_ROOTS if Path(root).is_dir()]
-
-    total = 0
-    for path in sorted(set(iter_files(roots)), key=str):
-        for finding in check_file(path):
-            total += 1
-            if not args.quiet:
-                print(
-                    f"{path}:{finding.line}: {finding.category.label}: {finding.message}"
-                )
-    print(f"\n{total} doxygen-style violation(s)", file=sys.stderr)
-    return 1 if total else 0
-
-
-if __name__ == "__main__":
-    sys.exit(main())

bin/pre-commit/clang_tidy_check.py

@@ -17,11 +17,9 @@ import subprocess
 import sys
 from pathlib import Path
 
-CLANG_TIDY_VERSION = 22
-
 
 def find_run_clang_tidy() -> str | None:
-    for candidate in (f"run-clang-tidy-{CLANG_TIDY_VERSION}", "run-clang-tidy"):
+    for candidate in ("run-clang-tidy-21", "run-clang-tidy"):
         if path := shutil.which(candidate):
             return path
     return None
@@ -46,8 +44,8 @@ def main():
     run_clang_tidy = find_run_clang_tidy()
     if not run_clang_tidy:
         print(
-            f"clang-tidy check failed: TIDY is enabled but neither "
-            f"'run-clang-tidy-{CLANG_TIDY_VERSION}' nor 'run-clang-tidy' was found in PATH.",
+            "clang-tidy check failed: TIDY is enabled but neither "
+            "'run-clang-tidy-21' nor 'run-clang-tidy' was found in PATH.",
             file=sys.stderr,
         )
         return 1

bin/pre-commit/test_check_doxygen_style.py

@@ -1,406 +0,0 @@
-#!/usr/bin/env python3
-"""
-Tests for check_doxygen_style.py.
-
-Run directly (no test framework needed):
-    ./bin/pre-commit/test_check_doxygen_style.py
-or under pytest:
-    pytest bin/pre-commit/test_check_doxygen_style.py
-"""
-
-import sys
-import textwrap
-
-from check_doxygen_style import Finding, check_source
-
-
-def findings_for(text: str) -> list[Finding]:
-    """Return the style violations for the given source text.
-
-    The text is dedented and its leading newline stripped, so fixtures can be
-    written as indented triple-quoted here-docs while keeping honest 1-based
-    line numbers.
-    """
-    text = textwrap.dedent(text).lstrip("\n")
-    return check_source(text)
-
-
-def labels_for(text: str) -> list[str]:
-    return [f.category.label for f in findings_for(text)]
-
-
-def messages_for(text: str) -> list[str]:
-    return [f.message for f in findings_for(text)]
-
-
-# --- well-formed input produces nothing -------------------------------------
-
-
-def test_clean_block_ok() -> None:
-    code = """
-    /**
-     * Brief.
-     *
-     * @tparam T a type
-     * @param x the x
-     * @return the result
-     */
-    """
-    assert findings_for(code) == []
-
-
-def test_blank_lines_inside_block_ok() -> None:
-    code = """
-    /**
-     * a
-     *
-     * b
-     */
-    """
-    assert findings_for(code) == []
-
-
-def test_member_and_divider_allowed() -> None:
-    assert findings_for("int x;  ///< ok member\n") == []
-    assert findings_for("//////////\n") == []
-    assert findings_for("//// text\n") == []
-
-
-# --- line-comment forms ------------------------------------------------------
-
-
-def test_triple_slash() -> None:
-    code = "/// doc\n"
-    assert labels_for(code) == ["triple-slash"]
-
-
-def test_qt_line() -> None:
-    code = "//! doc\n"
-    assert labels_for(code) == ["qt-line"]
-
-
-def test_qt_member() -> None:
-    code = "int x;  //!< doc\n"
-    assert labels_for(code) == ["qt-member"]
-
-
-def test_block_member() -> None:
-    code = "int x;  /**< doc */\n"
-    assert labels_for(code) == ["block-member"]
-
-
-def test_qt_block_member() -> None:
-    code = "int x;  /*!< doc */\n"
-    assert labels_for(code) == ["qt-block-member"]
-
-
-def test_doc_in_line_comment() -> None:
-    code = "// @param x\n"
-    assert labels_for(code) == ["doc-in-line-comment"]
-
-
-# --- block forms -------------------------------------------------------------
-
-
-def test_qt_comment() -> None:
-    code = """
-    /*!
-     * brief
-     */
-    """
-    assert labels_for(code) == ["qt-comment"]
-
-
-def test_qt_comment_single_line() -> None:
-    # /*! ... */ on one line -> qt-comment (plus single-line-block)
-    code = "/*! brief */\n"
-    assert labels_for(code) == ["qt-comment", "single-line-block"]
-
-
-def test_single_line_block() -> None:
-    code = "/** brief */\n"
-    assert labels_for(code) == ["single-line-block"]
-
-
-def test_single_line_markers_allowed() -> None:
-    for marker in ("@{", "@}", "@cond LABEL", "@endcond", "@file foo.h"):
-        code = f"/** {marker} */\n"
-        assert findings_for(code) == [], marker
-
-
-def test_text_on_opener() -> None:
-    code = """
-    /** text here
-     * more
-     */
-    """
-    assert labels_for(code) == ["text-on-opener"]
-
-
-def test_bare_continuation() -> None:
-    code = """
-    /**
-     * a
-       bare line
-     */
-    """
-    assert labels_for(code) == ["bare-continuation"]
-
-
-def test_over_indented_first_line() -> None:
-    code = """
-    /**
-     *   over
-     */
-    """
-    assert labels_for(code) == ["over-indented"]
-
-
-def test_over_indented_tag() -> None:
-    # a flush first line consumes "first content", isolating the tag check
-    code = """
-    /**
-     * brief
-     *   @param x
-     */
-    """
-    assert labels_for(code) == ["over-indented-tag"]
-
-
-def test_combined_marker() -> None:
-    code = """
-    /**
-     * @{
-     */
-    """
-    assert labels_for(code) == ["combined-marker"]
-
-
-def test_prose_label() -> None:
-    for word in ("Returns", "Throws", "Exceptions"):
-        code = f"""
-        /**
-         * {word}:
-         */
-        """
-        assert labels_for(code) == ["prose-label"], word
-
-
-def test_content_on_closer() -> None:
-    code = """
-    /**
-     * a
-     * b */
-    """
-    assert labels_for(code) == ["content-on-closer"]
-
-
-def test_plain_block_doc() -> None:
-    assert labels_for("/* @param x */\n") == ["plain-block-doc"]
-    assert findings_for("/* just an ordinary note */\n") == []
-
-
-def test_tag_order() -> None:
-    out_of_order = """
-    /**
-     * @param x
-     * @tparam T
-     */
-    """
-    assert labels_for(out_of_order) == ["tag-order"]
-
-    correct = """
-    /**
-     * @tparam T
-     * @param x
-     * @return r
-     */
-    """
-    assert findings_for(correct) == []
-
-    single = """
-    /**
-     * @param x
-     */
-    """
-    assert findings_for(single) == []  # single tag: never out of order
-
-
-# --- command spelling (must work on body/closer lines, not just the opener) --
-
-
-def test_backslash_command_on_body_line() -> None:
-    code = r"""
-    /**
-     * \brief x
-     */
-    """
-    assert labels_for(code) == ["backslash-command"]
-
-
-def test_backslash_command_suggests_canonical_spelling() -> None:
-    # a backslash + non-canonical spelling is fixed in one pass, not two:
-    # \sa -> @see (not @sa), \returns -> @return (not @returns)
-    sa = r"""
-    /**
-     * \sa other
-     */
-    """
-    assert messages_for(sa) == [r"use @see instead of \sa"]
-
-    returns = r"""
-    /**
-     * \returns x
-     */
-    """
-    assert messages_for(returns) == [r"use @return instead of \returns"]
-
-
-def test_wrong_command_on_body_line() -> None:
-    code = """
-    /**
-     * @returns x
-     */
-    """
-    assert labels_for(code) == ["wrong-command"]
-
-
-def test_body_line_commands_regression() -> None:
-    # regression: these live on body lines of a multi-line block
-    code = r"""
-    /**
-     * @returns bad
-     * @throw ex
-     * @sa other
-     * \param y
-     */
-    """
-    assert labels_for(code) == [
-        "wrong-command",
-        "wrong-command",
-        "wrong-command",
-        "backslash-command",
-    ]
-
-
-def test_command_on_closer_line() -> None:
-    code = """
-    /**
-     * a
-     * @sa b */
-    """
-    assert labels_for(code) == ["wrong-command", "content-on-closer"]
-
-
-def test_no_double_count_across_opener_body_closer() -> None:
-    code = """
-    /** @returns opener
-     * @throw body
-     * @sa closer */
-    """
-    assert labels_for(code).count("wrong-command") == 3
-
-
-def test_code_with_word_allowed() -> None:
-    # @code{.cpp} is valid Doxygen and must not be flagged
-    code = """
-    /**
-     * @code{.cpp}
-     * int x;
-     * @endcode
-     */
-    """
-    assert findings_for(code) == []
-
-
-# --- rendered message text ---------------------------------------------------
-
-
-def test_message_uses_category_description() -> None:
-    # a static category renders its default description
-    code = "/// doc\n"
-    assert messages_for(code) == ["use a /** ... */ block instead of ///"]
-
-
-def test_message_detail_overrides() -> None:
-    # dynamic categories render the offending text via Finding.detail
-    backslash = r"""
-    /**
-     * \param y
-     */
-    """
-    assert messages_for(backslash) == [r"use @param instead of \param"]
-
-    wrong = """
-    /**
-     * @returns x
-     */
-    """
-    assert messages_for(wrong) == ["use @return instead of @returns"]
-
-    prose = """
-    /**
-     * Throws:
-     */
-    """
-    assert messages_for(prose) == ['use @throws instead of prose "Throws:"']
-
-
-# --- robustness --------------------------------------------------------------
-
-
-def test_empty_file_no_crash() -> None:
-    assert findings_for("") == []
-
-
-def test_mid_line_plain_block_skipped() -> None:
-    # a /* opened mid-line (after code) and spanning lines is skipped, so its
-    # comment-like contents are not analyzed
-    code = """
-    int x = 0;  /* note: @returns is not a real tag here
-     * @param also not real
-     */
-    int y = 0;
-    """
-    assert findings_for(code) == []
-
-
-def test_unclosed_block_scanned_to_eof() -> None:
-    # an unterminated /** block is still scanned to EOF (no crash, body checked)
-    code = """
-    /**
-     * @returns x
-    """
-    assert labels_for(code) == ["wrong-command"]
-
-
-def test_banner_and_empty_comment_not_flagged() -> None:
-    code = """
-    /***
-     * banner
-     ***/
-    """
-    assert findings_for(code) == []
-    assert findings_for("/**/\n") == []
-
-
-def main() -> int:
-    tests = sorted(
-        (name, fn)
-        for name, fn in globals().items()
-        if name.startswith("test_") and callable(fn)
-    )
-    failed = 0
-    for name, fn in tests:
-        try:
-            fn()
-            print(f"PASS {name}")
-        except AssertionError as exc:
-            failed += 1
-            print(f"FAIL {name}: {exc!r}")
-    print(f"\n{len(tests) - failed}/{len(tests)} passed")
-    return 1 if failed else 0
-
-
-if __name__ == "__main__":
-    sys.exit(main())

cmake/scripts/codegen/templates/LedgerEntry.h.mako

@@ -177,9 +177,7 @@ ${field['typeData']['setter_type']} ${field['paramName']}${',' if i < len(requir
         object_ = *sle;
     }
 
-    /**
-     * @brief Ledger entry-specific field setters
-     */
+    /** @brief Ledger entry-specific field setters */
 % for field in fields:
 
     /**

cmake/scripts/codegen/templates/Transaction.h.mako

@@ -185,9 +185,7 @@ public:
         object_ = *tx;
     }
 
-    /**
-     * @brief Transaction-specific field setters
-     */
+    /** @brief Transaction-specific field setters */
 % for field in fields:
 
     /**

cspell.config.yaml

@@ -36,7 +36,9 @@ overrides:
       - /'[^']*'/g # single-quoted strings
       - /`[^`]*`/g # backtick strings
 suggestWords:
-  - unsynched->unsynced
+  - xprl->xrpl
+  - xprld->xrpld # cspell: disable-line not sure what this problem is....
+  - unsynched->unsynced # cspell: disable-line not sure what this problem is....
   - synched->synced
   - synch->sync
 words:
@@ -279,8 +281,6 @@ words:
   - sles
   - soci
   - socidb
-  - sponsee
-  - sponsees
   - SRPMS
   - sslws
   - statsd
@@ -302,7 +302,6 @@ words:
   - takerpays
   - ters
   - TMEndpointv2
-  - tparam
   - trixie
   - tx
   - txid
@@ -330,7 +329,6 @@ words:
   - unserviced
   - unshareable
   - unshares
-  - unsponsored
   - unsquelch
   - unsquelched
   - unsquelching

docs/build/environment.md

@@ -33,10 +33,9 @@ with a single command and without installing anything system-wide:
 nix --experimental-features 'nix-command flakes' develop
 ```
 
-On **Linux**, Nix also provides the compiler (GCC); on **macOS**, it provides
-Clang. If you instead opt to use your system-wide Apple Clang (via
-`nix develop .#apple-clang`), you need to manage its version yourself (see
-below).
+On **Linux**, Nix also provides the compiler (GCC). On **macOS**, the shell uses
+your **system-wide Apple Clang** as the compiler, so you still need to manage
+its version (see below).
 
 See [Using the Nix development shell](./nix.md) for installation and usage
 details, including how to select a different compiler.
@@ -49,10 +48,10 @@ details, including how to select a different compiler.
 
 ### macOS: managing the Apple Clang version
 
-If you use your system-wide Apple Clang on macOS (via `nix develop .#apple-clang`),
-the compiler version is whatever your installed Xcode (or Command Line Tools)
-provides. The following command should return a version greater than or equal to
-the [minimum required](#tested-compiler-versions):
+Because the Nix shell uses the system-wide Apple Clang on macOS, the compiler
+version is whatever your installed Xcode (or Command Line Tools) provides. The
+following command should return a version greater than or equal to the
+[minimum required](#tested-compiler-versions):
 
 ```bash
 clang --version

docs/build/nix.md

@@ -9,7 +9,7 @@ This guide explains how to use Nix to set up a reproducible development environm
 - **Reproducible environment**: Everyone gets the same versions of tools and compilers
 - **Matches CI**: The Linux CI runs in Docker images built from this exact Nix environment
 - **No system pollution**: Dependencies are isolated and don't affect your system packages
-- **Consistent compilers**: The GCC and Clang shells use the same versions as CI
+- **Multiple compiler versions**: Easily switch between different GCC and Clang versions
 - **Quick setup**: Get started with a single command
 - **Works on Linux and macOS**: Consistent experience across platforms
 
@@ -31,8 +31,8 @@ This will:
 
 - Download and set up all required development tools (CMake, Ninja, Conan, etc.)
 - Configure the appropriate compiler for your platform:
-  - **Linux**: GCC (provided by Nix)
-  - **macOS**: Clang (provided by Nix)
+  - **Linux**: GCC 15.2 (provided by Nix)
+  - **macOS**: Apple Clang (your system compiler)
 
 The first time you run this command, it will take a few minutes to download and build the environment. Subsequent runs will be much faster.
 
@@ -40,12 +40,12 @@ The first time you run this command, it will take a few minutes to download and
 
 - **Linux**: `nix develop` gives you a shell with all the tooling necessary to
   develop xrpld and with GCC 15.2 (also provided by Nix). There are no caveats.
-- **macOS**: `nix develop` gives you a full environment too, with Clang (and
-  every other tool, including Conan) provided by Nix. To use your system-wide
-  Apple Clang instead, enter `nix develop .#apple-clang`. Conan has no binary in
-  the Nix cache for macOS, so it is built from source the first time you enter
-  the shell, which makes the initial setup slower (this is handled
-  automatically; see [`nix/devshell.nix`](../../nix/devshell.nix)).
+- **macOS**: `nix develop` gives you a full environment too. The compiler is
+  your system-wide Apple Clang, while every other tool — including Conan — is
+  provided by Nix. Conan has no binary in the Nix cache for macOS, so it is
+  built from source the first time you enter the shell, which makes the initial
+  setup slower (this is handled automatically; see
+  [`nix/devshell.nix`](../../nix/devshell.nix)).
 
 > [!TIP]
 > To avoid typing `--experimental-features 'nix-command flakes'` every time, you can permanently enable flakes by creating `~/.config/nix/nix.conf`:
@@ -62,9 +62,7 @@ The first time you run this command, it will take a few minutes to download and
 
 ### Choosing a different compiler
 
-A compiler can be chosen by providing its name with the `.#` prefix, e.g. `nix develop .#clang`.
-The `.#gcc` and `.#clang` shells provide the same GCC and Clang versions used in CI
-(pinned in [`nix/packages.nix`](../../nix/packages.nix)).
+A compiler can be chosen by providing its name with the `.#` prefix, e.g. `nix develop .#gcc15`.
 Use `nix flake show` to see all the available development shells.
 
 Use `nix develop .#no-compiler` to use the compiler from your system.
@@ -72,11 +70,11 @@ Use `nix develop .#no-compiler` to use the compiler from your system.
 ### Example Usage
 
 ```bash
-# Use GCC (same version as CI)
-nix develop .#gcc
+# Use GCC 14
+nix develop .#gcc14
 
-# Use Clang (same version as CI)
-nix develop .#clang
+# Use Clang 19
+nix develop .#clang19
 
 # Use default for your platform
 nix develop
@@ -114,15 +112,7 @@ Once inside the Nix development shell, follow the standard [build instructions](
 
 [direnv](https://direnv.net/) or [nix-direnv](https://github.com/nix-community/nix-direnv) can automatically activate the Nix development shell when you enter the repository directory.
 
-This is also the most robust way to use the environment from **any shell** (bash, zsh, fish, …): direnv stays in your current shell and loads the environment _after_ your shell's startup files have run, so the Nix-provided tools take precedence over anything your shell configuration adds to `$PATH`.
-
-The repository already ships an `.envrc` at its root that activates the Nix flake development shell, so you don't need to create one. To use it:
-
-1. [Install direnv](https://direnv.net/docs/installation.html) and [hook it into your shell](https://direnv.net/docs/hook.html) (bash, zsh, fish, …). Installing [nix-direnv](https://github.com/nix-community/nix-direnv) as well is recommended: it caches the shell so that activation is near-instant after the first run.
-2. Run `direnv allow` once in the repository root. direnv will then load (and reload) the Nix development shell automatically whenever you enter the directory.
-
-> [!NOTE]
-> direnv only caches the `.direnv` directory (already listed in `.gitignore`); no other repository files are affected.
+This is also the most robust way to use the environment from **any shell** (bash, zsh, fish, …): direnv stays in your current shell and loads the environment _after_ your shell's startup files have run, so the Nix-provided tools take precedence over anything your shell configuration adds to `$PATH`. To use it, install direnv for your shell, then add an `.envrc` containing `use flake` at the repository root and run `direnv allow`.
 
 ## Conan and Prebuilt Packages
 

include/xrpl/basics/Archive.h

@@ -4,14 +4,13 @@
 
 namespace xrpl {
 
-/**
- * Extract a tar archive compressed with lz4
- *
- * @param src the path of the archive to be extracted
- * @param dst the directory to extract to
- *
- * @throws runtime_error
- */
+/** Extract a tar archive compressed with lz4
+
+    @param src the path of the archive to be extracted
+    @param dst the directory to extract to
+
+    @throws runtime_error
+*/
 void
 extractTarLz4(boost::filesystem::path const& src, boost::filesystem::path const& dst);
 

include/xrpl/basics/Blob.h

@@ -4,10 +4,9 @@
 
 namespace xrpl {
 
-/**
- * Storage for linear binary data.
- * Blocks of binary data appear often in various idioms and structures.
- */
+/** Storage for linear binary data.
+    Blocks of binary data appear often in various idioms and structures.
+*/
 using Blob = std::vector<unsigned char>;
 
 }  // namespace xrpl

include/xrpl/basics/Buffer.h

@@ -10,10 +10,9 @@
 
 namespace xrpl {
 
-/**
- * Like std::vector<char> but better.
- * Meets the requirements of BufferFactory.
- */
+/** Like std::vector<char> but better.
+    Meets the requirements of BufferFactory.
+*/
 class Buffer
 {
 private:
@@ -25,37 +24,30 @@ public:
 
     Buffer() = default;
 
-    /**
-     * Create an uninitialized buffer with the given size.
-     */
+    /** Create an uninitialized buffer with the given size. */
     explicit Buffer(std::size_t size)
         : p_((size != 0u) ? new std::uint8_t[size] : nullptr), size_(size)
     {
     }
 
-    /**
-     * Create a buffer as a copy of existing memory.
-     *
-     * @param data a pointer to the existing memory. If
-     *             size is non-zero, it must not be null.
-     * @param size size of the existing memory block.
-     */
+    /** Create a buffer as a copy of existing memory.
+
+        @param data a pointer to the existing memory. If
+                    size is non-zero, it must not be null.
+        @param size size of the existing memory block.
+    */
     Buffer(void const* data, std::size_t size) : Buffer(size)
     {
         if (size != 0u)
             std::memcpy(p_.get(), data, size);
     }
 
-    /**
-     * Copy-construct
-     */
+    /** Copy-construct */
     Buffer(Buffer const& other) : Buffer(other.p_.get(), other.size_)
     {
     }
 
-    /**
-     * Copy assign
-     */
+    /** Copy assign */
     Buffer&
     operator=(Buffer const& other)
     {
@@ -67,19 +59,17 @@ public:
         return *this;
     }
 
-    /**
-     * Move-construct.
-     * The other buffer is reset.
-     */
+    /** Move-construct.
+        The other buffer is reset.
+    */
     Buffer(Buffer&& other) noexcept : p_(std::move(other.p_)), size_(other.size_)
     {
         other.size_ = 0;
     }
 
-    /**
-     * Move-assign.
-     * The other buffer is reset.
-     */
+    /** Move-assign.
+        The other buffer is reset.
+    */
     Buffer&
     operator=(Buffer&& other) noexcept
     {
@@ -92,16 +82,12 @@ public:
         return *this;
     }
 
-    /**
-     * Construct from a slice
-     */
+    /** Construct from a slice */
     explicit Buffer(Slice s) : Buffer(s.data(), s.size())
     {
     }
 
-    /**
-     * Assign from slice
-     */
+    /** Assign from slice */
     Buffer&
     operator=(Slice s)
     {
@@ -115,9 +101,7 @@ public:
         return *this;
     }
 
-    /**
-     * Returns the number of bytes in the buffer.
-     */
+    /** Returns the number of bytes in the buffer. */
     [[nodiscard]] std::size_t
     size() const noexcept
     {
@@ -137,11 +121,10 @@ public:
         return Slice{p_.get(), size_};
     }
 
-    /**
-     * Return a pointer to beginning of the storage.
-     * @note The return type is guaranteed to be a pointer
-     *       to a single byte, to facilitate pointer arithmetic.
-     */
+    /** Return a pointer to beginning of the storage.
+        @note The return type is guaranteed to be a pointer
+              to a single byte, to facilitate pointer arithmetic.
+    */
     /** @{ */
     [[nodiscard]] std::uint8_t const*
     data() const noexcept
@@ -156,10 +139,9 @@ public:
     }
     /** @} */
 
-    /**
-     * Reset the buffer.
-     * All memory is deallocated. The resulting size is 0.
-     */
+    /** Reset the buffer.
+        All memory is deallocated. The resulting size is 0.
+    */
     void
     clear() noexcept
     {
@@ -167,10 +149,9 @@ public:
         size_ = 0;
     }
 
-    /**
-     * Reallocate the storage.
-     * Existing data, if any, is discarded.
-     */
+    /** Reallocate the storage.
+        Existing data, if any, is discarded.
+    */
     std::uint8_t*
     alloc(std::size_t n)
     {

include/xrpl/basics/CompressionAlgorithms.h

@@ -12,8 +12,7 @@
 
 namespace xrpl::compression_algorithms {
 
-/**
- * LZ4 block compression.
+/** LZ4 block compression.
  * @tparam BufferFactory Callable object or lambda.
  *     Takes the requested buffer size and returns allocated buffer pointer.
  * @param in Data to compress
@@ -81,8 +80,7 @@ lz4Decompress(
     return decompressedSize;
 }
 
-/**
- * LZ4 block decompression.
+/** LZ4 block decompression.
  * @tparam InputStream ZeroCopyInputStream
  * @param in Input source stream
  * @param inSize Size of compressed data

include/xrpl/basics/CountedObject.h

@@ -9,9 +9,7 @@
 
 namespace xrpl {
 
-/**
- * Manages all counted object types.
- */
+/** Manages all counted object types. */
 class CountedObjects
 {
 public:
@@ -25,11 +23,10 @@ public:
     getCounts(int minimumThreshold) const;
 
 public:
-    /**
-     * Implementation for @ref CountedObject.
-     *
-     * @internal
-     */
+    /** Implementation for @ref CountedObject.
+
+        @internal
+    */
     class Counter
     {
     public:
@@ -97,14 +94,13 @@ private:
 
 //------------------------------------------------------------------------------
 
-/**
- * Tracks the number of instances of an object.
- *
- * Derived classes have their instances counted automatically. This is used
- * for reporting purposes.
- *
- * @ingroup basics
- */
+/** Tracks the number of instances of an object.
+
+    Derived classes have their instances counted automatically. This is used
+    for reporting purposes.
+
+    @ingroup basics
+*/
 template <class Object>
 class CountedObject
 {

include/xrpl/basics/DecayingSample.h

@@ -6,10 +6,9 @@
 
 namespace xrpl {
 
-/**
- * Sampling function using exponential decay to provide a continuous value.
- * @tparam The number of seconds in the decay window.
- */
+/** Sampling function using exponential decay to provide a continuous value.
+    @tparam The number of seconds in the decay window.
+*/
 template <int Window, typename Clock>
 class DecayingSample
 {
@@ -20,16 +19,15 @@ public:
     DecayingSample() = delete;
 
     /**
-     * @param now Start time of DecayingSample.
-     */
+        @param now Start time of DecayingSample.
+    */
     explicit DecayingSample(time_point now) : value_(value_type()), when_(now)
     {
     }
 
-    /**
-     * Add a new sample.
-     * The value is first aged according to the specified time.
-     */
+    /** Add a new sample.
+        The value is first aged according to the specified time.
+    */
     value_type
     add(value_type value, time_point now)
     {
@@ -38,10 +36,9 @@ public:
         return value_ / Window;
     }
 
-    /**
-     * Retrieve the current value in normalized units.
-     * The samples are first aged according to the specified time.
-     */
+    /** Retrieve the current value in normalized units.
+        The samples are first aged according to the specified time.
+    */
     value_type
     value(time_point now)
     {
@@ -90,10 +87,9 @@ private:
 
 //------------------------------------------------------------------------------
 
-/**
- * Sampling function using exponential decay to provide a continuous value.
- * @tparam HalfLife The half life of a sample, in seconds.
- */
+/** Sampling function using exponential decay to provide a continuous value.
+    @tparam HalfLife The half life of a sample, in seconds.
+*/
 template <int HalfLife, class Clock>
 class DecayWindow
 {

include/xrpl/basics/IntrusivePointer.h

@@ -10,37 +10,33 @@ namespace xrpl {
 
 //------------------------------------------------------------------------------
 
-/**
- * Tag to create an intrusive pointer from another intrusive pointer by using a
- * static cast. This is useful to create an intrusive pointer to a derived
- * class from an intrusive pointer to a base class.
- */
+/** Tag to create an intrusive pointer from another intrusive pointer by using a
+    static cast. This is useful to create an intrusive pointer to a derived
+    class from an intrusive pointer to a base class.
+*/
 struct StaticCastTagSharedIntrusive
 {
 };
 
-/**
- * Tag to create an intrusive pointer from another intrusive pointer by using a
- * dynamic cast. This is useful to create an intrusive pointer to a derived
- * class from an intrusive pointer to a base class. If the cast fails an empty
- * (null) intrusive pointer is created.
- */
+/** Tag to create an intrusive pointer from another intrusive pointer by using a
+    dynamic cast. This is useful to create an intrusive pointer to a derived
+    class from an intrusive pointer to a base class. If the cast fails an empty
+    (null) intrusive pointer is created.
+*/
 struct DynamicCastTagSharedIntrusive
 {
 };
 
-/**
- * When creating or adopting a raw pointer, controls whether the strong count
- * is incremented or not. Use this tag to increment the strong count.
- */
+/** When creating or adopting a raw pointer, controls whether the strong count
+    is incremented or not. Use this tag to increment the strong count.
+*/
 struct SharedIntrusiveAdoptIncrementStrongTag
 {
 };
 
-/**
- * When creating or adopting a raw pointer, controls whether the strong count
- * is incremented or not. Use this tag to leave the strong count unchanged.
- */
+/** When creating or adopting a raw pointer, controls whether the strong count
+    is incremented or not. Use this tag to leave the strong count unchanged.
+*/
 struct SharedIntrusiveAdoptNoIncrementTag
 {
 };
@@ -54,21 +50,20 @@ concept CAdoptTag = std::is_same_v<T, SharedIntrusiveAdoptIncrementStrongTag> ||
 
 //------------------------------------------------------------------------------
 
-/**
- * A shared intrusive pointer class that supports weak pointers.
- *
- * This is meant to be used for SHAMapInnerNodes, but may be useful for other
- * cases. Since the reference counts are stored on the pointee, the pointee is
- * not destroyed until both the strong _and_ weak pointer counts go to zero.
- * When the strong pointer count goes to zero, the "partialDestructor" is
- * called. This can be used to destroy as much of the object as possible while
- * still retaining the reference counts. For example, for SHAMapInnerNodes the
- * children may be reset in that function. Note that std::shared_pointer WILL
- * run the destructor when the strong count reaches zero, but may not free the
- * memory used by the object until the weak count reaches zero. In xrpld, we
- * typically allocate shared pointers with the `make_shared` function. When
- * that is used, the memory is not reclaimed until the weak count reaches zero.
- */
+/** A shared intrusive pointer class that supports weak pointers.
+
+    This is meant to be used for SHAMapInnerNodes, but may be useful for other
+    cases. Since the reference counts are stored on the pointee, the pointee is
+    not destroyed until both the strong _and_ weak pointer counts go to zero.
+    When the strong pointer count goes to zero, the "partialDestructor" is
+    called. This can be used to destroy as much of the object as possible while
+    still retaining the reference counts. For example, for SHAMapInnerNodes the
+    children may be reset in that function. Note that std::shared_pointer WILL
+    run the destructor when the strong count reaches zero, but may not free the
+    memory used by the object until the weak count reaches zero. In xrpld, we
+    typically allocate shared pointers with the `make_shared` function. When
+    that is used, the memory is not reclaimed until the weak count reaches zero.
+*/
 template <class T>
 class SharedIntrusive
 {
@@ -116,9 +111,8 @@ public:
     operator=(
         SharedIntrusive<TT>&& rhs);  // NOLINT(cppcoreguidelines-rvalue-reference-param-not-moved)
 
-    /**
-     * Adopt the raw pointer. The strong reference may or may not be
-     * incremented, depending on the TAdoptTag
+    /** Adopt the raw pointer. The strong reference may or may not be
+        incremented, depending on the TAdoptTag
      */
     template <CAdoptTag TAdoptTag = SharedIntrusiveAdoptIncrementStrongTag>
     void
@@ -126,31 +120,27 @@ public:
 
     ~SharedIntrusive();
 
-    /**
-     * Create a new SharedIntrusive by statically casting the pointer
-     * controlled by the rhs param.
-     */
+    /** Create a new SharedIntrusive by statically casting the pointer
+        controlled by the rhs param.
+    */
     template <class TT>
     SharedIntrusive(StaticCastTagSharedIntrusive, SharedIntrusive<TT> const& rhs);
 
-    /**
-     * Create a new SharedIntrusive by statically casting the pointer
-     * controlled by the rhs param.
-     */
+    /** Create a new SharedIntrusive by statically casting the pointer
+       controlled by the rhs param.
+    */
     template <class TT>
     SharedIntrusive(StaticCastTagSharedIntrusive, SharedIntrusive<TT>&& rhs);
 
-    /**
-     * Create a new SharedIntrusive by dynamically casting the pointer
-     * controlled by the rhs param.
-     */
+    /** Create a new SharedIntrusive by dynamically casting the pointer
+       controlled by the rhs param.
+    */
     template <class TT>
     SharedIntrusive(DynamicCastTagSharedIntrusive, SharedIntrusive<TT> const& rhs);
 
-    /**
-     * Create a new SharedIntrusive by dynamically casting the pointer
-     * controlled by the rhs param.
-     */
+    /** Create a new SharedIntrusive by dynamically casting the pointer
+       controlled by the rhs param.
+    */
     template <class TT>
     SharedIntrusive(DynamicCastTagSharedIntrusive, SharedIntrusive<TT>&& rhs);
 
@@ -163,22 +153,17 @@ public:
     explicit
     operator bool() const noexcept;
 
-    /**
-     * Set the pointer to null, decrement the strong count, and run the
-     * appropriate release action.
-     */
+    /** Set the pointer to null, decrement the strong count, and run the
+        appropriate release action.
+      */
     void
     reset();
 
-    /**
-     * Get the raw pointer
-     */
+    /** Get the raw pointer */
     [[nodiscard]] T*
     get() const;
 
-    /**
-     * Return the strong count
-     */
+    /** Return the strong count */
     [[nodiscard]] std::size_t
     useCount() const;
 
@@ -196,51 +181,43 @@ public:
     friend class WeakIntrusive;
 
 private:
-    /**
-     * Return the raw pointer held by this object.
-     */
+    /** Return the raw pointer held by this object. */
     [[nodiscard]] T*
     unsafeGetRawPtr() const;
 
-    /**
-     * Exchange the current raw pointer held by this object with the given
-     * pointer. Decrement the strong count of the raw pointer previously held
-     * by this object and run the appropriate release action.
+    /** Exchange the current raw pointer held by this object with the given
+        pointer. Decrement the strong count of the raw pointer previously held
+        by this object and run the appropriate release action.
      */
     void
     unsafeReleaseAndStore(T* next);
 
-    /**
-     * Set the raw pointer directly. This is wrapped in a function so the class
-     * can support both atomic and non-atomic pointers in a future patch.
+    /** Set the raw pointer directly. This is wrapped in a function so the class
+        can support both atomic and non-atomic pointers in a future patch.
      */
     void
     unsafeSetRawPtr(T* p);
 
-    /**
-     * Exchange the raw pointer directly.
-     * This sets the raw pointer to the given value and returns the previous
-     * value. This is wrapped in a function so the class can support both
-     * atomic and non-atomic pointers in a future patch.
+    /** Exchange the raw pointer directly.
+        This sets the raw pointer to the given value and returns the previous
+        value. This is wrapped in a function so the class can support both
+        atomic and non-atomic pointers in a future patch.
      */
     T*
     unsafeExchange(T* p);
 
-    /**
-     * pointer to the type with an intrusive count
-     */
+    /** pointer to the type with an intrusive count */
     T* ptr_{nullptr};
 };
 
 //------------------------------------------------------------------------------
 
-/**
- * A weak intrusive pointer class for the SharedIntrusive pointer class.
- *
- * Note that this weak pointer class asks differently from normal weak pointer
- * classes. When the strong pointer count goes to zero, the "partialDestructor"
- * is called. See the comment on SharedIntrusive for a fuller explanation.
- */
+/** A weak intrusive pointer class for the SharedIntrusive pointer class.
+
+Note that this weak pointer class asks differently from normal weak pointer
+classes. When the strong pointer count goes to zero, the "partialDestructor"
+is called. See the comment on SharedIntrusive for a fuller explanation.
+*/
 template <class T>
 class WeakIntrusive
 {
@@ -270,62 +247,54 @@ public:
     WeakIntrusive&
     operator=(SharedIntrusive<TT> const& rhs);
 
-    /**
-     * Adopt the raw pointer and increment the weak count.
-     */
+    /** Adopt the raw pointer and increment the weak count. */
     void
     adopt(T* ptr);
 
     ~WeakIntrusive();
 
-    /**
-     * Get a strong pointer from the weak pointer, if possible. This will
-     * only return a seated pointer if the strong count on the raw pointer
-     * is non-zero before locking.
+    /** Get a strong pointer from the weak pointer, if possible. This will
+       only return a seated pointer if the strong count on the raw pointer
+       is non-zero before locking.
      */
     SharedIntrusive<T>
     lock() const;
 
-    /**
-     * Return true if the strong count is zero.
-     */
+    /** Return true if the strong count is zero. */
     [[nodiscard]] bool
     expired() const;
 
-    /**
-     * Set the pointer to null and decrement the weak count.
-     *
-     * Note: This may run the destructor if the strong count is zero.
-     */
+    /** Set the pointer to null and decrement the weak count.
+
+    Note: This may run the destructor if the strong count is zero.
+    */
     void
     reset();
 
 private:
     T* ptr_ = nullptr;
 
-    /**
-     * Decrement the weak count. This does _not_ set the raw pointer to
-     * null.
-     *
-     * Note: This may run the destructor if the strong count is zero.
-     */
+    /** Decrement the weak count. This does _not_ set the raw pointer to
+    null.
+
+    Note: This may run the destructor if the strong count is zero.
+    */
     void
     unsafeReleaseNoStore();
 };
 
 //------------------------------------------------------------------------------
 
-/**
- * A combination of a strong and a weak intrusive pointer stored in the
- * space of a single pointer.
- *
- * This class is similar to a `std::variant<SharedIntrusive,WeakIntrusive>`
- * with some optimizations. In particular, it uses a low-order bit to
- * determine if the raw pointer represents a strong pointer or a weak
- * pointer. It can also be quickly switched between its strong pointer and
- * weak pointer representations. This class is useful for storing intrusive
- * pointers in tagged caches.
- */
+/** A combination of a strong and a weak intrusive pointer stored in the
+    space of a single pointer.
+
+    This class is similar to a `std::variant<SharedIntrusive,WeakIntrusive>`
+    with some optimizations. In particular, it uses a low-order bit to
+    determine if the raw pointer represents a strong pointer or a weak
+    pointer. It can also be quickly switched between its strong pointer and
+    weak pointer representations. This class is useful for storing intrusive
+    pointers in tagged caches.
+  */
 
 template <class T>
 class SharedWeakUnion
@@ -367,83 +336,69 @@ public:
 
     ~SharedWeakUnion();
 
-    /**
-     * Return a strong pointer if this is already a strong pointer (i.e.
-     * don't lock the weak pointer. Use the `lock` method if that's what's
-     * needed)
+    /** Return a strong pointer if this is already a strong pointer (i.e.
+       don't lock the weak pointer. Use the `lock` method if that's what's
+       needed)
      */
     [[nodiscard]] SharedIntrusive<T>
     getStrong() const;
 
-    /**
-     * Return true if this is a strong pointer and the strong pointer is
-     * seated.
+    /** Return true if this is a strong pointer and the strong pointer is
+        seated.
      */
     explicit
     operator bool() const noexcept;
 
-    /**
-     * Set the pointer to null, decrement the appropriate ref count, and
-     * run the appropriate release action.
+    /** Set the pointer to null, decrement the appropriate ref count, and
+       run the appropriate release action.
      */
     void
     reset();
 
-    /**
-     * If this is a strong pointer, return the raw pointer. Otherwise
-     * return null.
+    /** If this is a strong pointer, return the raw pointer. Otherwise
+       return null.
      */
     [[nodiscard]] T*
     get() const;
 
-    /**
-     * If this is a strong pointer, return the strong count. Otherwise
+    /** If this is a strong pointer, return the strong count. Otherwise
      * return 0
      */
     [[nodiscard]] std::size_t
     useCount() const;
 
-    /**
-     * Return true if there is a non-zero strong count.
-     */
+    /** Return true if there is a non-zero strong count. */
     [[nodiscard]] bool
     expired() const;
 
-    /**
-     * If this is a strong pointer, return the strong pointer. Otherwise
-     * attempt to lock the weak pointer.
+    /** If this is a strong pointer, return the strong pointer. Otherwise
+        attempt to lock the weak pointer.
      */
     [[nodiscard]] SharedIntrusive<T>
     lock() const;
 
-    /**
-     * Return true is this represents a strong pointer.
-     */
+    /** Return true is this represents a strong pointer. */
     [[nodiscard]] bool
     isStrong() const;
 
-    /**
-     * Return true is this represents a weak pointer.
-     */
+    /** Return true is this represents a weak pointer. */
     [[nodiscard]] bool
     isWeak() const;
 
-    /**
-     * If this is a weak pointer, attempt to convert it to a strong
-     * pointer.
-     *
-     * @return true if successfully converted to a strong pointer (or was
-     *         already a strong pointer). Otherwise false.
-     */
+    /** If this is a weak pointer, attempt to convert it to a strong
+       pointer.
+
+        @return true if successfully converted to a strong pointer (or was
+                already a strong pointer). Otherwise false.
+      */
     bool
     convertToStrong();
 
-    /**
-     * If this is a strong pointer, attempt to convert it to a weak
-     * pointer.
-     *
-     * @return false if the pointer is null. Otherwise return true.
-     */
+    /** If this is a strong pointer, attempt to convert it to a weak
+       pointer.
+
+        @return false if the pointer is null. Otherwise return true.
+      */
     bool
     convertToWeak();
 
@@ -456,27 +411,23 @@ private:
     static constexpr std::uintptr_t kPtrMask = ~kTagMask;
 
 private:
-    /**
-     * Return the raw pointer held by this object.
+    /** Return the raw pointer held by this object.
      */
     [[nodiscard]] T*
     unsafeGetRawPtr() const;
 
     enum class RefStrength { Strong, Weak };
-    /**
-     * Set the raw pointer and tag bit directly.
+    /** Set the raw pointer and tag bit directly.
      */
     void
     unsafeSetRawPtr(T* p, RefStrength rs);
 
-    /**
-     * Set the raw pointer and tag bit to all zeros (strong null pointer).
+    /** Set the raw pointer and tag bit to all zeros (strong null pointer).
      */
     void unsafeSetRawPtr(std::nullptr_t);
 
-    /**
-     * Decrement the appropriate ref count, and run the appropriate release
-     * action. Note: this does _not_ set the raw pointer to null.
+    /** Decrement the appropriate ref count, and run the appropriate release
+        action. Note: this does _not_ set the raw pointer to null.
      */
     void
     unsafeReleaseNoStore();
@@ -484,13 +435,12 @@ private:
 
 //------------------------------------------------------------------------------
 
-/**
- * Create a shared intrusive pointer.
- *
- * Note: unlike std::shared_ptr, where there is an advantage of allocating
- * the pointer and control block together, there is no benefit for intrusive
- * pointers.
- */
+/** Create a shared intrusive pointer.
+
+    Note: unlike std::shared_ptr, where there is an advantage of allocating
+    the pointer and control block together, there is no benefit for intrusive
+    pointers.
+*/
 template <class TT, class... Args>
 SharedIntrusive<TT>
 makeSharedIntrusive(Args&&... args)

include/xrpl/basics/IntrusivePointer.ipp

@@ -641,9 +641,6 @@ template <class T>
 T*
 SharedWeakUnion<T>::unsafeGetRawPtr() const
 {
-    // tp_ packs a raw pointer together with a strength bit; recovering the
-    // pointer inherently requires an integer-to-pointer cast.
-    // NOLINTNEXTLINE(performance-no-int-to-ptr)
     return reinterpret_cast<T*>(tp_ & kPtrMask);
 }
 

include/xrpl/basics/IntrusiveRefCounts.h

@@ -8,38 +8,35 @@
 
 namespace xrpl {
 
-/**
- * Action to perform when releasing a strong pointer.
- *
- * noop: Do nothing. For example, a `noop` action will occur when a count is
- * decremented to a non-zero value.
- *
- * partialDestroy: Run the `partialDestructor`. This action will happen when a
- * strong count is decremented to zero and the weak count is non-zero.
- *
- * destroy: Run the destructor. This action will occur when either the strong
- * count or weak count is decremented and the other count is also zero.
+/** Action to perform when releasing a strong pointer.
+
+    noop: Do nothing. For example, a `noop` action will occur when a count is
+    decremented to a non-zero value.
+
+    partialDestroy: Run the `partialDestructor`. This action will happen when a
+    strong count is decremented to zero and the weak count is non-zero.
+
+    destroy: Run the destructor. This action will occur when either the strong
+    count or weak count is decremented and the other count is also zero.
  */
 enum class ReleaseStrongRefAction { NoOp, PartialDestroy, Destroy };
 
-/**
- * Action to perform when releasing a weak pointer.
- *
- * noop: Do nothing. For example, a `noop` action will occur when a count is
- * decremented to a non-zero value.
- *
- * destroy: Run the destructor. This action will occur when either the strong
- * count or weak count is decremented and the other count is also zero.
+/** Action to perform when releasing a weak pointer.
+
+    noop: Do nothing. For example, a `noop` action will occur when a count is
+    decremented to a non-zero value.
+
+    destroy: Run the destructor. This action will occur when either the strong
+    count or weak count is decremented and the other count is also zero.
  */
 enum class ReleaseWeakRefAction { NoOp, Destroy };
 
-/**
- * Implement the strong count, weak count, and bit flags for an intrusive
- * pointer.
- *
- * A class can satisfy the requirements of an xrpl::IntrusivePointer by
- * inheriting from this class.
- */
+/** Implement the strong count, weak count, and bit flags for an intrusive
+    pointer.
+
+    A class can satisfy the requirements of an xrpl::IntrusivePointer by
+    inheriting from this class.
+  */
 struct IntrusiveRefCounts
 {
     virtual ~IntrusiveRefCounts() noexcept;
@@ -108,123 +105,109 @@ private:
     static constexpr size_t kFieldTypeBits = sizeof(FieldType) * 8;
     static constexpr FieldType kOne = 1;
 
-    /**
-     * `refCounts` consists of four fields that are treated atomically:
-     *
-     * 1. Strong count. This is a count of the number of shared pointers that
-     * hold a reference to this object. When the strong counts goes to zero,
-     * if the weak count is zero, the destructor is run. If the weak count is
-     * non-zero when the strong count goes to zero then the partialDestructor
-     * is run.
-     *
-     * 2. Weak count. This is a count of the number of weak pointer that hold
-     * a reference to this object. When the weak count goes to zero and the
-     * strong count is also zero, then the destructor is run.
-     *
-     * 3. Partial destroy started bit. This bit is set if the
-     * `partialDestructor` function has been started (or is about to be
-     * started). This is used to prevent the destructor from running
-     * concurrently with the partial destructor. This can easily happen when
-     * the last strong pointer release its reference in one thread and starts
-     * the partialDestructor, while in another thread the last weak pointer
-     * goes out of scope and starts the destructor while the partialDestructor
-     * is still running. Both a start and finished bit is needed to handle a
-     * corner-case where the last strong pointer goes out of scope, then then
-     * last `weakPointer` goes out of scope, but this happens before the
-     * `partialDestructor` bit is set. It would be possible to use a single
-     * bit if it could also be set atomically when the strong count goes to
-     * zero and the weak count is non-zero, but that would add complexity (and
-     * likely slow down common cases as well).
-     *
-     * 4. Partial destroy finished bit. This bit is set when the
-     * `partialDestructor` has finished running. See (3) above for more
-     * information.
-     */
+    /** `refCounts` consists of four fields that are treated atomically:
+
+         1. Strong count. This is a count of the number of shared pointers that
+         hold a reference to this object. When the strong counts goes to zero,
+         if the weak count is zero, the destructor is run. If the weak count is
+         non-zero when the strong count goes to zero then the partialDestructor
+         is run.
+
+         2. Weak count. This is a count of the number of weak pointer that hold
+         a reference to this object. When the weak count goes to zero and the
+         strong count is also zero, then the destructor is run.
+
+         3. Partial destroy started bit. This bit is set if the
+         `partialDestructor` function has been started (or is about to be
+         started). This is used to prevent the destructor from running
+         concurrently with the partial destructor. This can easily happen when
+         the last strong pointer release its reference in one thread and starts
+         the partialDestructor, while in another thread the last weak pointer
+         goes out of scope and starts the destructor while the partialDestructor
+         is still running. Both a start and finished bit is needed to handle a
+         corner-case where the last strong pointer goes out of scope, then then
+         last `weakPointer` goes out of scope, but this happens before the
+         `partialDestructor` bit is set. It would be possible to use a single
+         bit if it could also be set atomically when the strong count goes to
+         zero and the weak count is non-zero, but that would add complexity (and
+         likely slow down common cases as well).
+
+         4. Partial destroy finished bit. This bit is set when the
+         `partialDestructor` has finished running. See (3) above for more
+         information.
+
+         */
 
     mutable std::atomic<FieldType> refCounts_{kStrongDelta};
 
-    /**
-     * Amount to change the strong count when adding or releasing a reference
-     *
-     *   Note: The strong count is stored in the low `StrongCountNumBits` bits
-     * of refCounts
-     */
+    /**  Amount to change the strong count when adding or releasing a reference
+
+         Note: The strong count is stored in the low `StrongCountNumBits` bits
+       of refCounts
+      */
     static constexpr FieldType kStrongDelta = 1;
 
-    /**
-     * Amount to change the weak count when adding or releasing a reference
-     *
-     * Note: The weak count is stored in the high `WeakCountNumBits` bits of
-     * refCounts
-     */
+    /**  Amount to change the weak count when adding or releasing a reference
+
+         Note: The weak count is stored in the high `WeakCountNumBits` bits of
+         refCounts
+      */
     static constexpr FieldType kWeakDelta = (kOne << kStrongCountNumBits);
 
-    /**
-     * Flag that is set when the partialDestroy function has started running
-     * (or is about to start running).
-     *
-     * See description of the `refCounts` field for a fuller description of
-     * this field.
-     */
+    /**  Flag that is set when the partialDestroy function has started running
+         (or is about to start running).
+
+         See description of the `refCounts` field for a fuller description of
+         this field.
+      */
     static constexpr FieldType kPartialDestroyStartedMask = (kOne << (kFieldTypeBits - 1));
 
-    /**
-     * Flag that is set when the partialDestroy function has finished running
-     *
-     * See description of the `refCounts` field for a fuller description of
-     * this field.
-     */
+    /**  Flag that is set when the partialDestroy function has finished running
+
+         See description of the `refCounts` field for a fuller description of
+         this field.
+      */
     static constexpr FieldType kPartialDestroyFinishedMask = (kOne << (kFieldTypeBits - 2));
 
-    /**
-     * Mask that will zero out all the `count` bits and leave the tag bits
-     * unchanged.
-     */
+    /** Mask that will zero out all the `count` bits and leave the tag bits
+        unchanged.
+      */
     static constexpr FieldType kTagMask = kPartialDestroyStartedMask | kPartialDestroyFinishedMask;
 
-    /**
-     * Mask that will zero out the `tag` bits and leave the count bits
-     * unchanged.
-     */
+    /** Mask that will zero out the `tag` bits and leave the count bits
+        unchanged.
+      */
     static constexpr FieldType kValueMask = ~kTagMask;
 
-    /**
-     * Mask that will zero out everything except the strong count.
+    /** Mask that will zero out everything except the strong count.
      */
     static constexpr FieldType kStrongMask = ((kOne << kStrongCountNumBits) - 1) & kValueMask;
 
-    /**
-     * Mask that will zero out everything except the weak count.
+    /** Mask that will zero out everything except the weak count.
      */
     static constexpr FieldType kWeakMask =
         (((kOne << kWeakCountNumBits) - 1) << kStrongCountNumBits) & kValueMask;
 
-    /**
-     * Unpack the count and tag fields from the packed atomic integer form.
-     */
+    /** Unpack the count and tag fields from the packed atomic integer form. */
     struct RefCountPair
     {
         CountType strong;
         CountType weak;
-        /**
-         * The `partialDestroyStartedBit` is set to on when the partial
-         * destroy function is started. It is not a boolean; it is a uint32
-         * with all bits zero with the possible exception of the
-         * `partialDestroyStartedMask` bit. This is done so it can be directly
-         * masked into the `combinedValue`.
+        /**  The `partialDestroyStartedBit` is set to on when the partial
+             destroy function is started. It is not a boolean; it is a uint32
+             with all bits zero with the possible exception of the
+             `partialDestroyStartedMask` bit. This is done so it can be directly
+             masked into the `combinedValue`.
          */
         FieldType partialDestroyStartedBit{0};
-        /**
-         * The `partialDestroyFinishedBit` is set to on when the partial
-         * destroy function has finished.
+        /**  The `partialDestroyFinishedBit` is set to on when the partial
+             destroy function has finished.
          */
         FieldType partialDestroyFinishedBit{0};
         RefCountPair(FieldType v) noexcept;
         RefCountPair(CountType s, CountType w) noexcept;
 
-        /**
-         * Convert back to the packed integer form.
-         */
+        /** Convert back to the packed integer form. */
         [[nodiscard]] FieldType
         combinedValue() const noexcept;
 
@@ -232,10 +215,9 @@ private:
             static_cast<CountType>((kOne << kStrongCountNumBits) - 1);
         static constexpr CountType kMaxWeakValue =
             static_cast<CountType>((kOne << kWeakCountNumBits) - 1);
-        /**
-         * Put an extra margin to detect when running up against limits.
-         * This is only used in debug code, and is useful if we reduce the
-         * number of bits in the strong and weak counts (to 16 and 14 bits).
+        /**  Put an extra margin to detect when running up against limits.
+             This is only used in debug code, and is useful if we reduce the
+             number of bits in the strong and weak counts (to 16 and 14 bits).
          */
         static constexpr CountType kCheckStrongMaxValue = kMaxStrongValue - 32;
         static constexpr CountType kCheckWeakMaxValue = kMaxWeakValue - 32;

include/xrpl/basics/LocalValue.h

@@ -70,15 +70,11 @@ public:
     {
     }
 
-    /**
-     * Stores instance of T specific to the calling coroutine or thread.
-     */
+    /** Stores instance of T specific to the calling coroutine or thread. */
     T&
     operator*();
 
-    /**
-     * Stores instance of T specific to the calling coroutine or thread.
-     */
+    /** Stores instance of T specific to the calling coroutine or thread. */
     T*
     operator->()
     {

include/xrpl/basics/Log.h

@@ -16,9 +16,7 @@
 
 namespace xrpl {
 
-/**
- * Manages partitions for logging.
- */
+/** Manages partitions for logging. */
 class Logs
 {
 private:
@@ -42,81 +40,69 @@ private:
         writeAlways(beast::Severity level, std::string const& text) override;
     };
 
-    /**
-     * Manages a system file containing logged output.
-     * The system file remains open during program execution. Interfaces
-     * are provided for interoperating with standard log management
-     * tools like logrotate(8):
-     *     http://linuxcommand.org/man_pages/logrotate8.html
-     * @note None of the listed interfaces are thread-safe.
-     */
+    /** Manages a system file containing logged output.
+        The system file remains open during program execution. Interfaces
+        are provided for interoperating with standard log management
+        tools like logrotate(8):
+            http://linuxcommand.org/man_pages/logrotate8.html
+        @note None of the listed interfaces are thread-safe.
+    */
     class File
     {
     public:
-        /**
-         * Construct with no associated system file.
-         * A system file may be associated later with @ref open.
-         * @see open
-         */
+        /** Construct with no associated system file.
+            A system file may be associated later with @ref open.
+            @see open
+        */
         File();
 
-        /**
-         * Destroy the object.
-         * If a system file is associated, it will be flushed and closed.
-         */
+        /** Destroy the object.
+            If a system file is associated, it will be flushed and closed.
+        */
         ~File() = default;
 
-        /**
-         * Determine if a system file is associated with the log.
-         * @return `true` if a system file is associated and opened for
-         * writing.
-         */
+        /** Determine if a system file is associated with the log.
+            @return `true` if a system file is associated and opened for
+            writing.
+        */
         [[nodiscard]] bool
         isOpen() const noexcept;
 
-        /**
-         * Associate a system file with the log.
-         * If the file does not exist an attempt is made to create it
-         * and open it for writing. If the file already exists an attempt is
-         * made to open it for appending.
-         * If a system file is already associated with the log, it is closed
-         * first.
-         * @return `true` if the file was opened.
-         */
+        /** Associate a system file with the log.
+            If the file does not exist an attempt is made to create it
+            and open it for writing. If the file already exists an attempt is
+            made to open it for appending.
+            If a system file is already associated with the log, it is closed
+            first.
+            @return `true` if the file was opened.
+        */
         bool
         open(boost::filesystem::path const& path);
 
-        /**
-         * Close and re-open the system file associated with the log
-         * This assists in interoperating with external log management tools.
-         * @return `true` if the file was opened.
-         */
+        /** Close and re-open the system file associated with the log
+            This assists in interoperating with external log management tools.
+            @return `true` if the file was opened.
+        */
         bool
         closeAndReopen();
 
-        /**
-         * Close the system file if it is open.
-         */
+        /** Close the system file if it is open. */
         void
         close();
 
-        /**
-         * write to the log file.
-         * Does nothing if there is no associated system file.
-         */
+        /** write to the log file.
+            Does nothing if there is no associated system file.
+        */
         void
         write(char const* text);
 
-        /**
-         * write to the log file and append an end of line marker.
-         * Does nothing if there is no associated system file.
-         */
+        /** write to the log file and append an end of line marker.
+            Does nothing if there is no associated system file.
+        */
         void
         writeln(char const* text);
 
-        /**
-         * Write to the log file using std::string.
-         */
+        /** Write to the log file using std::string. */
         /** @{ */
         void
         write(std::string const& str)
@@ -237,21 +223,19 @@ private:
 //------------------------------------------------------------------------------
 // Debug logging:
 
-/**
- * Set the sink for the debug journal.
- *
- * @param sink unique_ptr to new debug Sink.
- * @return unique_ptr to the previous Sink.  nullptr if there was no Sink.
- */
+/** Set the sink for the debug journal.
+
+    @param sink unique_ptr to new debug Sink.
+    @return unique_ptr to the previous Sink.  nullptr if there was no Sink.
+*/
 std::unique_ptr<beast::Journal::Sink>
 setDebugLogSink(std::unique_ptr<beast::Journal::Sink> sink);
 
-/**
- * Returns a debug journal.
- * The journal may drain to a null sink, so its output
- * may never be seen. Never use it for critical
- * information.
- */
+/** Returns a debug journal.
+    The journal may drain to a null sink, so its output
+    may never be seen. Never use it for critical
+    information.
+*/
 beast::Journal
 debugLog();
 

include/xrpl/basics/MathUtilities.h

@@ -6,8 +6,7 @@
 
 namespace xrpl {
 
-/**
- * Calculate one number divided by another number in percentage.
+/** Calculate one number divided by another number in percentage.
  * The result is rounded up to the next integer, and capped in the range [0,100]
  * E.g. calculatePercent(1, 100) = 1 because 1/100 = 0.010000
  *      calculatePercent(1, 99) = 2 because 1/99 = 0.010101
@@ -20,7 +19,7 @@ namespace xrpl {
  * @return the percentage, in [0, 100]
  *
  * @note total cannot be zero.
- */
+ * */
 constexpr std::size_t
 calculatePercent(std::size_t count, std::size_t total)
 {

include/xrpl/basics/Number.h

@@ -14,6 +14,7 @@
 #include <stdexcept>
 #include <string>
 #include <type_traits>
+#include <unordered_map>
 #include <utility>
 
 namespace xrpl {
@@ -47,54 +48,46 @@ isPowerOfTen(T value)
 
 namespace detail {
 
-/**
- * Builds a table of the powers of 10
+/** Builds a table of the powers of 10
  *
  * This function is marked consteval, so it can only be run in
  * a constexpr context. This assures that it is and can only be run at
  * compile time. Doing it at runtime would be pretty wasteful and
  * inefficient.
  */
-constexpr std::size_t kUint64Digits = 20;
-[[maybe_unused]] constexpr std::size_t kUint128Digits = 39;
-
-template <typename T, std::size_t Digits>
-consteval std::array<T, Digits>
+constexpr std::size_t kInt64Digits = 20;
+consteval std::array<std::uint64_t, kInt64Digits>
 buildPowersOfTen()
 {
-    std::array<T, Digits> result{};
+    std::array<std::uint64_t, kInt64Digits> result{};
 
-    T power = 1;
+    std::uint64_t power = 1;
     std::size_t exponent = 0;
     // end the loop early so it doesn't overflow;
     for (; exponent < result.size() - 1; ++exponent, power *= 10)
     {
         result[exponent] = power;
-        if (power > std::numeric_limits<T>::max() / 10)
+        if (power > std::numeric_limits<std::uint64_t>::max() / 10)
             throw std::logic_error("Power of 10 table is too big");
     }
     result[exponent] = power;
-    if (power < std::numeric_limits<T>::max() / 10)
-        throw std::logic_error("Power of 10 table is not big enough for the given type");
+    if (power < std::numeric_limits<std::uint64_t>::max() / 10)
+        throw std::logic_error("Power of 10 table is not big enough for the uint64_t type");
 
     return result;
 }
 
 }  // namespace detail
 
-template <typename T = std::uint64_t, std::size_t Digits = detail::kUint64Digits>
-constexpr std::array<T, Digits> kPowerOfTenImpl = detail::buildPowersOfTen<T, Digits>();
-
-constexpr auto kPowerOfTen = kPowerOfTenImpl<std::uint64_t, detail::kUint64Digits>;
+constexpr std::array<std::uint64_t, detail::kInt64Digits> kPowerOfTen = detail::buildPowersOfTen();
 
 static_assert(kPowerOfTen[0] == 1);
 static_assert(kPowerOfTen[1] == 10);
 static_assert(kPowerOfTen[10] == 10'000'000'000);
 static_assert(
-    isPowerOfTen(kPowerOfTen.back()) && *logTen(kPowerOfTen.back()) == detail::kUint64Digits - 1);
+    isPowerOfTen(kPowerOfTen.back()) && *logTen(kPowerOfTen.back()) == detail::kInt64Digits - 1);
 
-/**
- * MantissaRange defines a range for the mantissa of a normalized Number.
+/** MantissaRange defines a range for the mantissa of a normalized Number.
  *
  * The mantissa is in the range [min, max], where
  * * min is a power of 10, and
@@ -131,37 +124,17 @@ struct MantissaRange final
 {
     using rep = std::uint64_t;
 
-    // NOLINTBEGIN(readability-enum-initial-value)
-    // The values don't matter, except for Large
     enum class MantissaScale {
-        // Small can be removed when either featureSingleAssetVault or featureLendingProtocol are
-        // retired
         Small,
         // LargeLegacy can be removed when fixCleanup3_2_0 is retired
         LargeLegacy,
-        // Large320 can be removed when fixCleanup3_3_0 is retired
-        Large320,
-        // If Large330 is ever the only remaining "Large*" entry, it can be renamed to just "Large".
-        Large330,
-        // Large is a de-facto alias for "the latest", and is only here for backward compatibility
-        // in the extremely unlikely case that a downstream project made use of it. Note that
-        // because the behavior changed, this may still be a breaking change.
-        Large = Large330,
+        Large,
     };
-    // NOLINTEND(readability-enum-initial-value)
 
-    // This entire enum can be removed when the last relevant amendment is retired
-    enum class CuspRoundingFix : std::uint8_t {
-        // Disabled can be removed when fixCleanup3_2_0 is retired
-        Disabled = 0,
-        // Enabled320 can be removed when fixCleanup3_3_0 is retired
-        Enabled320 = 1,
-        // If we ever get to the point that there's only one entry, remove the entire enum
-        Enabled330 = 2,
-        // Enabled is a de-facto alias for "the latest", and is only here for backward compatibility
-        // in the extremely unlikely case that a downstream project made use of it. Note that
-        // because the behavior changed, this may still be a breaking change.
-        Enabled = Enabled330,
+    // This entire enum can be removed when fixCleanup3_2_0 is retired
+    enum class CuspRoundingFix : bool {
+        Disabled = false,
+        Enabled = true,
     };
 
     explicit constexpr MantissaRange(MantissaScale sc) : scale(sc)
@@ -172,27 +145,13 @@ struct MantissaRange final
     int const log{getExponent(scale)};
     rep const min{getMin(scale, log)};
     rep const max{(min * 10) - 1};
-    CuspRoundingFix const cuspRoundingFix{isCuspFixEnabled(scale)};
+    CuspRoundingFix const cuspRoundingFixEnabled{isCuspFixEnabled(scale)};
+
+    static MantissaRange const&
+    getMantissaRange(MantissaScale scale);
 
     static std::set<MantissaScale> const&
-    getAllScales()
-    {
-        static std::set<MantissaRange::MantissaScale> const kScales = {
-            MantissaRange::MantissaScale::Small,
-            MantissaRange::MantissaScale::LargeLegacy,
-            MantissaRange::MantissaScale::Large320,
-            MantissaRange::MantissaScale::Large330,
-        };
-        return kScales;
-    }
-
-    class Access
-    {
-        static constexpr MantissaRange const&
-        mantissaRange(MantissaScale scale);
-
-        friend Number;
-    };
+    getAllScales();
 
 private:
     static constexpr int
@@ -203,8 +162,7 @@ private:
             case MantissaScale::Small:
                 return 15;
             case MantissaScale::LargeLegacy:
-            case MantissaScale::Large320:
-            case MantissaScale::Large330:
+            case MantissaScale::Large:
                 return 18;
             // LCOV_EXCL_START
             default:
@@ -233,24 +191,24 @@ private:
             case MantissaScale::Small:
             case MantissaScale::LargeLegacy:
                 return CuspRoundingFix::Disabled;
-            case MantissaScale::Large320:
-                return CuspRoundingFix::Enabled320;
-            case MantissaScale::Large330:
-                return CuspRoundingFix::Enabled330;
+            case MantissaScale::Large:
+                return CuspRoundingFix::Enabled;
             default:
                 // If called in a constexpr context, this throw assures that the build fails if an
                 // invalid scale is used.
                 throw std::runtime_error("Unknown mantissa scale");  // LCOV_EXCL_LINE
         }
     }
+
+    static std::unordered_map<MantissaScale, MantissaRange> const&
+    getRanges();
 };
 
 // Like std::integral, but only 64-bit integral types.
 template <class T>
 concept Integral64 = std::is_same_v<T, std::int64_t> || std::is_same_v<T, std::uint64_t>;
 
-/**
- * Number is a floating point type that can represent a wide range of values.
+/** Number is a floating point type that can represent a wide range of values.
  *
  * It can represent all values that can be represented by an STAmount -
  * regardless of asset type - XRPAmount, MPTAmount, and IOUAmount, with at least
@@ -346,6 +304,7 @@ concept Integral64 = std::is_same_v<T, std::int64_t> || std::is_same_v<T, std::u
  * disable the amendments that control the mantissa range choice
  * (SingleAssetVault and LendingProtocol), and/or check if either of those
  * amendments are enabled to determine which result to expect.
+ *
  */
 class Number final
 {
@@ -431,11 +390,10 @@ public:
     static Number
     lowest() noexcept;
 
-    /**
-     * Conversions to Number are implicit and conversions away from Number
-     * are explicit. This design encourages and facilitates the use of Number
-     * as the preferred type for floating point arithmetic as it makes
-     * "mixed mode" more convenient, e.g. MPTAmount + Number.
+    /** Conversions to Number are implicit and conversions away from Number
+     *  are explicit. This design encourages and facilitates the use of Number
+     *  as the preferred type for floating point arithmetic as it makes
+     *  "mixed mode" more convenient, e.g. MPTAmount + Number.
      */
     explicit
     operator rep() const;  // round to nearest, even on tie
@@ -490,9 +448,7 @@ public:
         return l.mantissa_ < r.mantissa_;
     }
 
-    /**
-     * Return the sign of the amount
-     */
+    /** Return the sign of the amount */
     [[nodiscard]] constexpr int
     signum() const noexcept
     {
@@ -546,16 +502,14 @@ public:
     static RoundingMode
     setround(RoundingMode inMode);
 
-    /**
-     * Returns which mantissa scale is currently in use for normalization.
+    /** Returns which mantissa scale is currently in use for normalization.
      *
      * If you think you need to call this outside of unit tests, no you don't.
      */
     static MantissaRange::MantissaScale
     getMantissaScale();
 
-    /**
-     * Changes which mantissa scale is used for normalization.
+    /** Changes which mantissa scale is used for normalization.
      *
      * If you think you need to call this outside of unit tests, no you don't.
      */
@@ -600,17 +554,10 @@ private:
     // changing the values inside the range.
     static thread_local std::reference_wrapper<MantissaRange const> kRange;
 
-    class Guard;
-
     void
     normalize(MantissaRange const& range);
 
-    // Guard has the fields that we need, as well as MantissaRange, so if we have a guard, use that
-    void
-    normalize(Guard const& guard);
-
-    /**
-     * Normalize Number components to an arbitrary range.
+    /** Normalize Number components to an arbitrary range.
      *
      * min/maxMantissa are parameters because this function is used by both
      * normalize(), which reads from kRange, and by normalizeToRange,
@@ -624,7 +571,7 @@ private:
         int& exponent,
         internalrep const& minMantissa,
         internalrep const& maxMantissa,
-        MantissaRange::CuspRoundingFix cuspRoundingFix);
+        MantissaRange::CuspRoundingFix cuspRoundingFixEnabled);
 
     template <class T>
     friend void
@@ -634,7 +581,7 @@ private:
         int& exponent,
         MantissaRange::rep const& minMantissa,
         MantissaRange::rep const& maxMantissa,
-        MantissaRange::CuspRoundingFix cuspRoundingFix,
+        MantissaRange::CuspRoundingFix cuspRoundingFixEnabled,
         bool dropped);
 
     [[nodiscard]] bool
@@ -652,6 +599,8 @@ private:
     // UB, and can vary across compilers.
     static internalrep
     externalToInternal(rep mantissa);
+
+    class Guard;
 };
 
 constexpr Number::Number(bool negative, internalrep mantissa, int exponent, Unchecked) noexcept
@@ -686,8 +635,7 @@ inline Number::Number(rep mantissa) : Number{mantissa, 0}
 {
 }
 
-/**
- * Returns the mantissa of the external view of the Number.
+/** Returns the mantissa of the external view of the Number.
  *
  * Please see the "---- External Interface ----" section of the class
  * documentation for an explanation of why the internal value may be modified.
@@ -708,8 +656,7 @@ Number::mantissa() const noexcept
     return sign * static_cast<Number::rep>(m);
 }
 
-/**
- * Returns the exponent of the external view of the Number.
+/** Returns the exponent of the external view of the Number.
  *
  * Please see the "---- External Interface ----" section of the class
  * documentation for an explanation of why the internal value may be modified.
@@ -915,11 +862,21 @@ squelch(Number const& x, Number const& limit) noexcept
     return x;
 }
 
-std::string
-to_string(MantissaRange::MantissaScale const& scale);
-
-std::string
-to_string(Number::RoundingMode const& round);
+inline std::string
+to_string(MantissaRange::MantissaScale const& scale)
+{
+    switch (scale)
+    {
+        case MantissaRange::MantissaScale::Small:
+            return "small";
+        case MantissaRange::MantissaScale::LargeLegacy:
+            return "largeLegacy";
+        case MantissaRange::MantissaScale::Large:
+            return "large";
+        default:
+            throw std::runtime_error("Bad scale");
+    }
+}
 
 class SaveNumberRoundMode
 {
@@ -958,10 +915,10 @@ public:
     operator=(NumberRoundModeGuard const&) = delete;
 };
 
-/**
- * Sets the new scale and restores the old scale when it leaves scope.
+/** Sets the new scale and restores the old scale when it leaves scope.
  *
  * If you think you need to use this class outside of unit tests, no you don't.
+ *
  */
 class NumberMantissaScaleGuard
 {

include/xrpl/basics/RangeSet.h

@@ -13,25 +13,23 @@
 
 namespace xrpl {
 
-/**
- * A closed interval over the domain T.
- *
- * For an instance ClosedInterval c, this represents the closed interval
- * (c.first(), c.last()).  A single element interval has c.first() == c.last().
- *
- * This is simply a type-alias for boost interval container library interval
- * set, so users should consult that documentation for available supporting
- * member and free functions.
- */
+/** A closed interval over the domain T.
+
+    For an instance ClosedInterval c, this represents the closed interval
+    (c.first(), c.last()).  A single element interval has c.first() == c.last().
+
+    This is simply a type-alias for boost interval container library interval
+    set, so users should consult that documentation for available supporting
+    member and free functions.
+*/
 template <class T>
 using ClosedInterval = boost::icl::closed_interval<T>;
 
-/**
- * Create a closed range interval
- *
- * Helper function to create a closed range interval without having to qualify
- * the template argument.
- */
+/** Create a closed range interval
+
+    Helper function to create a closed range interval without having to qualify
+    the template argument.
+*/
 template <class T>
 ClosedInterval<T>
 range(T low, T high)
@@ -39,30 +37,28 @@ range(T low, T high)
     return ClosedInterval<T>(low, high);
 }
 
-/**
- * A set of closed intervals over the domain T.
- *
- * Represents a set of values of the domain T using the minimum number
- * of disjoint ClosedInterval<T>.  This is useful to represent ranges of
- * T where a few instances are missing, e.g. the set 1-5,8-9,11-14.
- *
- * This is simply a type-alias for boost interval container library interval
- * set, so users should consult that documentation for available supporting
- * member and free functions.
- */
+/** A set of closed intervals over the domain T.
+
+    Represents a set of values of the domain T using the minimum number
+    of disjoint ClosedInterval<T>.  This is useful to represent ranges of
+    T where a few instances are missing, e.g. the set 1-5,8-9,11-14.
+
+    This is simply a type-alias for boost interval container library interval
+    set, so users should consult that documentation for available supporting
+    member and free functions.
+*/
 template <class T>
 using RangeSet = boost::icl::interval_set<T, std::less, ClosedInterval<T>>;
 
-/**
- * Convert a ClosedInterval to a styled string
- *
- * The styled string is
- *     "c.first()-c.last()"  if c.first() != c.last()
- *     "c.first()" if c.first() == c.last()
- *
- * @param ci The closed interval to convert
- * @return The style string
- */
+/** Convert a ClosedInterval to a styled string
+
+    The styled string is
+        "c.first()-c.last()"  if c.first() != c.last()
+        "c.first()" if c.first() == c.last()
+
+    @param ci The closed interval to convert
+    @return The style string
+*/
 template <class T>
 std::string
 to_string(ClosedInterval<T> const& ci)
@@ -72,15 +68,14 @@ to_string(ClosedInterval<T> const& ci)
     return std::to_string(ci.first()) + "-" + std::to_string(ci.last());
 }
 
-/**
- * Convert the given RangeSet to a styled string.
- *
- * The styled string representation is the set of disjoint intervals joined
- * by commas.  The string "empty" is returned if the set is empty.
- *
- * @param rs The rangeset to convert
- * @return The styled string
- */
+/** Convert the given RangeSet to a styled string.
+
+    The styled string representation is the set of disjoint intervals joined
+    by commas.  The string "empty" is returned if the set is empty.
+
+    @param rs The rangeset to convert
+    @return The styled string
+*/
 template <class T>
 std::string
 to_string(RangeSet<T> const& rs)
@@ -96,16 +91,15 @@ to_string(RangeSet<T> const& rs)
     return s;
 }
 
-/**
- * Convert the given styled string to a RangeSet.
- *
- * The styled string representation is the set
- * of disjoint intervals joined by commas.
- *
- * @param rs The set to be populated
- * @param s The styled string to convert
- * @return True on successfully converting styled string
- */
+/** Convert the given styled string to a RangeSet.
+
+    The styled string representation is the set
+    of disjoint intervals joined by commas.
+
+    @param rs The set to be populated
+    @param s The styled string to convert
+    @return True on successfully converting styled string
+*/
 template <class T>
 [[nodiscard]] bool
 fromString(RangeSet<T>& rs, std::string const& s)
@@ -167,15 +161,14 @@ fromString(RangeSet<T>& rs, std::string const& s)
     return result;
 }
 
-/**
- * Find the largest value not in the set that is less than a given value.
- *
- * @param rs The set of interest
- * @param t The value that must be larger than the result
- * @param minVal (Default is 0) The smallest allowed value
- * @return The largest v such that minV <= v < t and !contains(rs, v) or
- *         std::nullopt if no such v exists.
- */
+/** Find the largest value not in the set that is less than a given value.
+
+    @param rs The set of interest
+    @param t The value that must be larger than the result
+    @param minVal (Default is 0) The smallest allowed value
+    @return The largest v such that minV <= v < t and !contains(rs, v) or
+            std::nullopt if no such v exists.
+*/
 template <class T>
 std::optional<T>
 prevMissing(RangeSet<T> const& rs, T t, T minVal = 0)

include/xrpl/basics/Resolver.h

@@ -15,29 +15,22 @@ public:
 
     virtual ~Resolver() = 0;
 
-    /**
-     * Issue an asynchronous stop request.
-     */
+    /** Issue an asynchronous stop request. */
     virtual void
     stopAsync() = 0;
 
-    /**
-     * Issue a synchronous stop request.
-     */
+    /** Issue a synchronous stop request. */
     virtual void
     stop() = 0;
 
-    /**
-     * Issue a synchronous start request.
-     */
+    /** Issue a synchronous start request. */
     virtual void
     start() = 0;
 
-    /**
-     * resolve all hostnames on the list
-     * @param names the names to be resolved
-     * @param handler the handler to call
-     */
+    /** resolve all hostnames on the list
+        @param names the names to be resolved
+        @param handler the handler to call
+    */
     /** @{ */
     template <class Handler>
     void

include/xrpl/basics/SharedWeakCachePointer.h

@@ -7,14 +7,13 @@
 
 namespace xrpl {
 
-/**
- * A combination of a std::shared_ptr and a std::weak_pointer.
- *
- *
- * This class is a wrapper to a `std::variant<std::shared_ptr,std::weak_ptr>`
- * This class is useful for storing intrusive pointers in tagged caches using less
- * memory than storing both pointers directly.
- */
+/** A combination of a std::shared_ptr and a std::weak_pointer.
+
+
+This class is a wrapper to a `std::variant<std::shared_ptr,std::weak_ptr>`
+This class is useful for storing intrusive pointers in tagged caches using less
+memory than storing both pointers directly.
+*/
 
 template <class T>
 class SharedWeakCachePointer
@@ -49,79 +48,65 @@ public:
 
     ~SharedWeakCachePointer();
 
-    /**
-     * Return a strong pointer if this is already a strong pointer (i.e. don't
-     * lock the weak pointer. Use the `lock` method if that's what's needed)
+    /** Return a strong pointer if this is already a strong pointer (i.e. don't
+        lock the weak pointer. Use the `lock` method if that's what's needed)
      */
     [[nodiscard]] std::shared_ptr<T> const&
     getStrong() const;
 
-    /**
-     * Return true if this is a strong pointer and the strong pointer is
-     * seated.
+    /** Return true if this is a strong pointer and the strong pointer is
+        seated.
      */
     explicit
     operator bool() const noexcept;
 
-    /**
-     * Set the pointer to null, decrement the appropriate ref count, and run
-     * the appropriate release action.
+    /** Set the pointer to null, decrement the appropriate ref count, and run
+        the appropriate release action.
      */
     void
     reset();
 
-    /**
-     * If this is a strong pointer, return the raw pointer. Otherwise return
-     * null.
+    /** If this is a strong pointer, return the raw pointer. Otherwise return
+        null.
      */
     [[nodiscard]] T*
     get() const;
 
-    /**
-     * If this is a strong pointer, return the strong count. Otherwise return 0
+    /** If this is a strong pointer, return the strong count. Otherwise return 0
      */
     [[nodiscard]] std::size_t
     useCount() const;
 
-    /**
-     * Return true if there is a non-zero strong count.
-     */
+    /** Return true if there is a non-zero strong count. */
     [[nodiscard]] bool
     expired() const;
 
-    /**
-     * If this is a strong pointer, return the strong pointer. Otherwise
-     * attempt to lock the weak pointer.
+    /** If this is a strong pointer, return the strong pointer. Otherwise
+        attempt to lock the weak pointer.
      */
     [[nodiscard]] std::shared_ptr<T>
     lock() const;
 
-    /**
-     * Return true is this represents a strong pointer.
-     */
+    /** Return true is this represents a strong pointer. */
     [[nodiscard]] bool
     isStrong() const;
 
-    /**
-     * Return true is this represents a weak pointer.
-     */
+    /** Return true is this represents a weak pointer. */
     [[nodiscard]] bool
     isWeak() const;
 
-    /**
-     * If this is a weak pointer, attempt to convert it to a strong pointer.
-     *
-     * @return true if successfully converted to a strong pointer (or was
-     *         already a strong pointer). Otherwise false.
-     */
+    /** If this is a weak pointer, attempt to convert it to a strong pointer.
+
+        @return true if successfully converted to a strong pointer (or was
+                already a strong pointer). Otherwise false.
+      */
     bool
     convertToStrong();
 
-    /**
-     * If this is a strong pointer, attempt to convert it to a weak pointer.
-     *
-     * @return false if the pointer is null. Otherwise return true.
-     */
+    /** If this is a strong pointer, attempt to convert it to a weak pointer.
+
+        @return false if the pointer is null. Otherwise return true.
+      */
     bool
     convertToWeak();
 

include/xrpl/basics/SlabAllocator.h

@@ -33,9 +33,7 @@ class SlabAllocator
 
     static_assert(alignof(Type) == 8 || alignof(Type) == 4);
 
-    /**
-     * A block of memory that is owned by a slab allocator
-     */
+    /** A block of memory that is owned by a slab allocator */
     struct SlabBlock
     {
         // A mutex to protect the freelist for this block:
@@ -82,9 +80,7 @@ class SlabAllocator
         SlabBlock&
         operator=(SlabBlock&& other) = delete;
 
-        /**
-         * Determines whether the given pointer belongs to this allocator
-         */
+        /** Determines whether the given pointer belongs to this allocator */
         bool
         own(std::uint8_t const* pIn) const noexcept
         {
@@ -111,15 +107,14 @@ class SlabAllocator
             return ret;
         }
 
-        /**
-         * Return an item to this allocator's freelist.
-         *
-         * @param ptr The pointer to the chunk of memory being deallocated.
-         *
-         * @note This is a dangerous, private interface; the item being
-         *       returned should belong to this allocator. Debug builds
-         *       will check and assert if this is not the case. Release
-         *       builds will not.
+        /** Return an item to this allocator's freelist.
+
+            @param ptr The pointer to the chunk of memory being deallocated.
+
+            @note This is a dangerous, private interface; the item being
+                  returned should belong to this allocator. Debug builds
+                  will check and assert if this is not the case. Release
+                  builds will not.
          */
         void
         deallocate(std::uint8_t* ptr) noexcept
@@ -150,14 +145,13 @@ private:
     std::size_t const slabSize_;
 
 public:
-    /**
-     * Constructs a slab allocator able to allocate objects of a fixed size
-     *
-     * @param count the number of items the slab allocator can allocate; note
-     *              that a count of 0 is valid and means that the allocator
-     *              is, effectively, disabled. This can be very useful in some
-     *              contexts (e.g. when minimal memory usage is needed) and
-     *              allows for graceful failure.
+    /** Constructs a slab allocator able to allocate objects of a fixed size
+
+        @param count the number of items the slab allocator can allocate; note
+                     that a count of 0 is valid and means that the allocator
+                     is, effectively, disabled. This can be very useful in some
+                     contexts (e.g. when minimal memory usage is needed) and
+                     allows for graceful failure.
      */
     constexpr explicit SlabAllocator(
         std::size_t extra,
@@ -185,20 +179,17 @@ public:
     //        shutdown process up could make this possible.
     ~SlabAllocator() = default;
 
-    /**
-     * Returns the size of the memory block this allocator returns.
-     */
+    /** Returns the size of the memory block this allocator returns. */
     [[nodiscard]] constexpr std::size_t
     size() const noexcept
     {
         return itemSize_;
     }
 
-    /**
-     * Returns a suitably aligned pointer, if one is available.
-     *
-     * @return a pointer to a block of memory from the allocator, or
-     *         nullptr if the allocator can't satisfy this request.
+    /** Returns a suitably aligned pointer, if one is available.
+
+        @return a pointer to a block of memory from the allocator, or
+                nullptr if the allocator can't satisfy this request.
      */
     std::uint8_t*
     allocate() noexcept
@@ -259,13 +250,12 @@ public:
         return slab->allocate();
     }
 
-    /**
-     * Returns the memory block to the allocator.
-     *
-     * @param ptr A pointer to a memory block.
-     * @param size If non-zero, a hint as to the size of the block.
-     * @return true if this memory block belonged to the allocator and has
-     *              been released; false otherwise.
+    /** Returns the memory block to the allocator.
+
+        @param ptr A pointer to a memory block.
+        @param size If non-zero, a hint as to the size of the block.
+        @return true if this memory block belonged to the allocator and has
+                     been released; false otherwise.
      */
     bool
     deallocate(std::uint8_t* ptr) noexcept
@@ -288,9 +278,7 @@ public:
     }
 };
 
-/**
- * A collection of slab allocators of various sizes for a given type.
- */
+/** A collection of slab allocators of various sizes for a given type. */
 template <typename Type>
 class SlabAllocatorSet
 {
@@ -357,14 +345,13 @@ public:
 
     ~SlabAllocatorSet() = default;
 
-    /**
-     * Returns a suitably aligned pointer, if one is available.
-     *
-     * @param extra The number of extra bytes, above and beyond the size of
-     *              the object, that should be returned by the allocator.
-     *
-     * @return a pointer to a block of memory, or nullptr if the allocator
-     *         can't satisfy this request.
+    /** Returns a suitably aligned pointer, if one is available.
+
+        @param extra The number of extra bytes, above and beyond the size of
+                     the object, that should be returned by the allocator.
+
+        @return a pointer to a block of memory, or nullptr if the allocator
+                can't satisfy this request.
      */
     std::uint8_t*
     allocate(std::size_t extra) noexcept
@@ -381,13 +368,12 @@ public:
         return nullptr;
     }
 
-    /**
-     * Returns the memory block to the allocator.
-     *
-     * @param ptr A pointer to a memory block.
-     *
-     * @return true if this memory block belonged to one of the allocators
-     *              in this set and has been released; false otherwise.
+    /** Returns the memory block to the allocator.
+
+        @param ptr A pointer to a memory block.
+
+        @return true if this memory block belonged to one of the allocators
+                     in this set and has been released; false otherwise.
      */
     bool
     deallocate(std::uint8_t* ptr) noexcept

include/xrpl/basics/Slice.h

@@ -16,13 +16,12 @@
 
 namespace xrpl {
 
-/**
- * An immutable linear range of bytes.
- *
- * A fully constructed Slice is guaranteed to be in a valid state.
- * A Slice is lightweight and copyable, it retains no ownership
- * of the underlying memory.
- */
+/** An immutable linear range of bytes.
+
+    A fully constructed Slice is guaranteed to be in a valid state.
+    A Slice is lightweight and copyable, it retains no ownership
+    of the underlying memory.
+*/
 class Slice
 {
 private:
@@ -33,37 +32,30 @@ public:
     using value_type = std::uint8_t;
     using const_iterator = value_type const*;
 
-    /**
-     * Default constructed Slice has length 0.
-     */
+    /** Default constructed Slice has length 0. */
     Slice() noexcept = default;
 
     Slice(Slice const&) noexcept = default;
     Slice&
     operator=(Slice const&) noexcept = default;
 
-    /**
-     * Create a slice pointing to existing memory.
-     */
+    /** Create a slice pointing to existing memory. */
     Slice(void const* data, std::size_t size) noexcept
         : data_(reinterpret_cast<std::uint8_t const*>(data)), size_(size)
     {
     }
 
-    /**
-     * Return `true` if the byte range is empty.
-     */
+    /** Return `true` if the byte range is empty. */
     [[nodiscard]] bool
     empty() const noexcept
     {
         return size_ == 0;
     }
 
-    /**
-     * Returns the number of bytes in the storage.
-     *
-     * This may be zero for an empty range.
-     */
+    /** Returns the number of bytes in the storage.
+
+        This may be zero for an empty range.
+    */
     /** @{ */
     [[nodiscard]] std::size_t
     size() const noexcept
@@ -78,20 +70,17 @@ public:
     }
     /** @} */
 
-    /**
-     * Return a pointer to beginning of the storage.
-     * @note The return type is guaranteed to be a pointer
-     *       to a single byte, to facilitate pointer arithmetic.
-     */
+    /** Return a pointer to beginning of the storage.
+        @note The return type is guaranteed to be a pointer
+              to a single byte, to facilitate pointer arithmetic.
+    */
     [[nodiscard]] std::uint8_t const*
     data() const noexcept
     {
         return data_;
     }
 
-    /**
-     * Access raw bytes.
-     */
+    /** Access raw bytes. */
     std::uint8_t
     operator[](std::size_t i) const noexcept
     {
@@ -99,9 +88,7 @@ public:
         return data_[i];
     }
 
-    /**
-     * Advance the buffer.
-     */
+    /** Advance the buffer. */
     /** @{ */
     Slice&
     operator+=(std::size_t n)
@@ -121,9 +108,7 @@ public:
     }
     /** @} */
 
-    /**
-     * Shrinks the slice by moving its start forward by n characters.
-     */
+    /** Shrinks the slice by moving its start forward by n characters. */
     void
     removePrefix(std::size_t n)
     {
@@ -131,9 +116,7 @@ public:
         size_ -= n;
     }
 
-    /**
-     * Shrinks the slice by moving its end backward by n characters.
-     */
+    /** Shrinks the slice by moving its end backward by n characters. */
     void
     removeSuffix(std::size_t n)
     {
@@ -164,17 +147,16 @@ public:
         return data_ + size_;
     }
 
-    /**
-     * Return a "sub slice" of given length starting at the given position
-     *
-     * Note that the subslice encompasses the range [pos, pos + rCount),
-     * where rCount is the smaller of count and size() - pos.
-     *
-     * @param pos position of the first character
-     * @count requested length
-     *
-     * @return The requested subslice, if the request is valid.
-     * @throws std::out_of_range if pos > size()
+    /** Return a "sub slice" of given length starting at the given position
+
+        Note that the subslice encompasses the range [pos, pos + rCount),
+        where rCount is the smaller of count and size() - pos.
+
+        @param pos position of the first character
+        @count requested length
+
+        @returns The requested subslice, if the request is valid.
+        @throws std::out_of_range if pos > size()
      */
     [[nodiscard]] Slice
     substr(std::size_t pos, std::size_t count = std::numeric_limits<std::size_t>::max()) const
@@ -229,17 +211,15 @@ operator<<(Stream& s, Slice const& v)
 }
 
 template <class T, std::size_t N>
-Slice
+std::enable_if_t<std::is_same_v<T, char> || std::is_same_v<T, unsigned char>, Slice>
 makeSlice(std::array<T, N> const& a)
-    requires(std::is_same_v<T, char> || std::is_same_v<T, unsigned char>)
 {
     return Slice(a.data(), a.size());
 }
 
 template <class T, class Alloc>
-Slice
+std::enable_if_t<std::is_same_v<T, char> || std::is_same_v<T, unsigned char>, Slice>
 makeSlice(std::vector<T, Alloc> const& v)
-    requires(std::is_same_v<T, char> || std::is_same_v<T, unsigned char>)
 {
     return Slice(v.data(), v.size());
 }

include/xrpl/basics/StringUtilities.h

@@ -17,16 +17,15 @@
 
 namespace xrpl {
 
-/**
- * Format arbitrary binary data as an SQLite "blob literal".
- *
- * In SQLite, blob literals must be encoded when used in a query. Per
- * https://sqlite.org/lang_expr.html#literal_values_constants_ they are
- * encoded as string literals containing hexadecimal data and preceded
- * by a single 'X' character.
- *
- * @param blob An arbitrary blob of binary data
- * @return The input, encoded as a blob literal.
+/** Format arbitrary binary data as an SQLite "blob literal".
+
+    In SQLite, blob literals must be encoded when used in a query. Per
+    https://sqlite.org/lang_expr.html#literal_values_constants_ they are
+    encoded as string literals containing hexadecimal data and preceded
+    by a single 'X' character.
+
+    @param blob An arbitrary blob of binary data
+    @return The input, encoded as a blob literal.
  */
 std::string
 sqlBlobLiteral(Blob const& blob);
@@ -131,12 +130,11 @@ trimWhitespace(std::string str);
 std::optional<std::uint64_t>
 toUInt64(std::string const& s);
 
-/**
- * Determines if the given string looks like a TOML-file hosting domain.
- *
- * Do not use this function to determine if a particular string is a valid
- * domain, as this function may reject domains that are otherwise valid and
- * doesn't check whether the TLD is valid.
+/** Determines if the given string looks like a TOML-file hosting domain.
+
+    Do not use this function to determine if a particular string is a valid
+    domain, as this function may reject domains that are otherwise valid and
+    doesn't check whether the TLD is valid.
  */
 bool
 isProperlyFormedTomlDomain(std::string_view domain);

include/xrpl/basics/TaggedCache.h

@@ -41,19 +41,18 @@ struct ReplaceDynamically;
 
 }  // namespace detail
 
-/**
- * Map/cache combination.
- * This class implements a cache and a map. The cache keeps objects alive
- * in the map. The map allows multiple code paths that reference objects
- * with the same tag to get the same actual object.
- *
- * So long as data is in the cache, it will stay in memory.
- * If it stays in memory even after it is ejected from the cache,
- * the map will track it.
- *
- * @note Callers must not modify data objects that are stored in the cache
- *       unless they hold their own lock over all cache operations.
- */
+/** Map/cache combination.
+    This class implements a cache and a map. The cache keeps objects alive
+    in the map. The map allows multiple code paths that reference objects
+    with the same tag to get the same actual object.
+
+    So long as data is in the cache, it will stay in memory.
+    If it stays in memory even after it is ejected from the cache,
+    the map will track it.
+
+    @note Callers must not modify data objects that are stored in the cache
+          unless they hold their own lock over all cache operations.
+*/
 template <
     class Key,
     class T,
@@ -83,15 +82,11 @@ public:
         beast::insight::Collector::ptr const& collector = beast::insight::NullCollector::make());
 
 public:
-    /**
-     * Return the clock associated with the cache.
-     */
+    /** Return the clock associated with the cache. */
     clock_type&
     clock();
 
-    /**
-     * Returns the number of items in the container.
-     */
+    /** Returns the number of items in the container. */
     std::size_t
     size() const;
 
@@ -110,10 +105,9 @@ public:
     void
     reset();
 
-    /**
-     * Refresh the last access time on a key if present.
-     * @return `true` If the key was found.
-     */
+    /** Refresh the last access time on a key if present.
+        @return `true` If the key was found.
+    */
     template <class KeyComparable>
     bool
     touchIfExists(KeyComparable const& key);
@@ -136,15 +130,14 @@ private:
         SharedPointerType const&,
         SharedPointerType&>;
 
-    /**
-     * Shared implementation of the canonicalize family.
-     *
-     * `policy` selects how a collision is resolved when `key` already exists:
-     * detail::ReplaceCached, detail::ReplaceClient or
-     * detail::ReplaceDynamically. For ReplaceDynamically `replaceCallback` is
-     * invoked with the existing strong pointer and returns whether to replace
-     * the cached value with `data`; for the tag policies it is unused.
-     */
+    /** Shared implementation of the canonicalize family.
+
+        `policy` selects how a collision is resolved when `key` already exists:
+        detail::ReplaceCached, detail::ReplaceClient or
+        detail::ReplaceDynamically. For ReplaceDynamically `replaceCallback` is
+        invoked with the existing strong pointer and returns whether to replace
+        the cached value with `data`; for the tag policies it is unused.
+    */
     template <class Policy, class Callback = std::nullptr_t>
     bool
     canonicalizeImpl(
@@ -154,82 +147,76 @@ private:
         Callback&& replaceCallback = nullptr);
 
 public:
-    /**
-     * Replace aliased objects with originals.
-     *
-     * Due to concurrency it is possible for two separate objects with
-     * the same content and referring to the same unique "thing" to exist.
-     * This routine eliminates the duplicate and performs a replacement
-     * on the callers shared pointer if needed.
-     *
-     * `replaceCallback` is a callable taking the existing strong pointer and
-     * returning whether to replace the cached value with `data` (true) or to
-     * keep the cached value and write it back into `data` (false). Because the
-     * write-back case mutates `data`, `data` must be writable.
-     *
-     * @param key The key corresponding to the object
-     * @param data A shared pointer to the data corresponding to the object.
-     * @param replaceCallback A callable (existing strong pointer -> bool).
-     *
-     * @return `true` if an existing live entry was found and used; `false` if a new entry was
-     *         inserted or an expired tracked entry was re-cached.
-     */
+    /** Replace aliased objects with originals.
+
+        Due to concurrency it is possible for two separate objects with
+        the same content and referring to the same unique "thing" to exist.
+        This routine eliminates the duplicate and performs a replacement
+        on the callers shared pointer if needed.
+
+        `replaceCallback` is a callable taking the existing strong pointer and
+        returning whether to replace the cached value with `data` (true) or to
+        keep the cached value and write it back into `data` (false). Because the
+        write-back case mutates `data`, `data` must be writable.
+
+        @param key The key corresponding to the object
+        @param data A shared pointer to the data corresponding to the object.
+        @param replaceCallback A callable (existing strong pointer -> bool).
+
+        @return `true` if an existing live entry was found and used; `false` if a new entry was
+                inserted or an expired tracked entry was re-cached.
+    **/
     template <class Callback>
     bool
     canonicalize(key_type const& key, SharedPointerType& data, Callback&& replaceCallback);
 
-    /**
-     * Insert/update the canonical entry for `key`, always replacing the
-     * cached value with `data`.
-     *
-     * If an entry already exists for `key`, the cached value is unconditionally
-     * replaced with `data`; otherwise `data` is inserted. `data` is never
-     * written back, so it may be const.
-     *
-     * @param key The key corresponding to the object.
-     * @param data A shared pointer to the data corresponding to the object.
-     *
-     * @return `true` if an existing live entry was found and used; `false` if a new entry was
-     *         inserted or an expired tracked entry was re-cached.
-     */
+    /** Insert/update the canonical entry for `key`, always replacing the
+        cached value with `data`.
+
+        If an entry already exists for `key`, the cached value is unconditionally
+        replaced with `data`; otherwise `data` is inserted. `data` is never
+        written back, so it may be const.
+
+        @param key The key corresponding to the object.
+        @param data A shared pointer to the data corresponding to the object.
+
+        @return `true` if an existing live entry was found and used; `false` if a new entry was
+                inserted or an expired tracked entry was re-cached.
+    **/
     bool
     canonicalizeReplaceCache(key_type const& key, SharedPointerType const& data);
 
-    /**
-     * Insert the canonical entry for `key`, keeping any existing cached value.
-     *
-     * If an entry already exists for `key`, the cached value is kept and
-     * written back into `data` so the caller ends up with the canonical
-     * object; otherwise `data` is inserted. Because `data` may be overwritten
-     * it must be writable.
-     *
-     * @param key The key corresponding to the object.
-     * @param data A shared pointer to the data corresponding to the object;
-     *             updated to the canonical value when one already exists.
-     *
-     * @return `true` if an existing live entry was found and used; `false` if a new entry was
-     *         inserted or an expired tracked entry was re-cached.
-     */
+    /** Insert the canonical entry for `key`, keeping any existing cached value.
+
+        If an entry already exists for `key`, the cached value is kept and
+        written back into `data` so the caller ends up with the canonical
+        object; otherwise `data` is inserted. Because `data` may be overwritten
+        it must be writable.
+
+        @param key The key corresponding to the object.
+        @param data A shared pointer to the data corresponding to the object;
+                    updated to the canonical value when one already exists.
+
+        @return `true` if an existing live entry was found and used; `false` if a new entry was
+                inserted or an expired tracked entry was re-cached.
+    **/
     bool
     canonicalizeReplaceClient(key_type const& key, SharedPointerType& data);
 
     SharedPointerType
     fetch(key_type const& key);
 
-    /**
-     * Insert the element into the container.
-     * If the key already exists, nothing happens.
-     * @return `true` If the element was inserted
-     */
+    /** Insert the element into the container.
+        If the key already exists, nothing happens.
+        @return `true` If the element was inserted
+    */
     template <class ReturnType = bool>
     auto
-    insert(key_type const& key, T const& value) -> ReturnType
-        requires(!IsKeyCache);
+    insert(key_type const& key, T const& value) -> std::enable_if_t<!IsKeyCache, ReturnType>;
 
     template <class ReturnType = bool>
     auto
-    insert(key_type const& key) -> ReturnType
-        requires IsKeyCache;
+    insert(key_type const& key) -> std::enable_if_t<IsKeyCache, ReturnType>;
 
     // VFALCO NOTE It looks like this returns a copy of the data in
     //             the output parameter 'data'. This could be expensive.
@@ -246,18 +233,15 @@ public:
     getKeys() const;
 
     // CachedSLEs functions.
-    /**
-     * Returns the fraction of cache hits.
-     */
+    /** Returns the fraction of cache hits. */
     double
     rate() const;
 
-    /**
-     * Fetch an item from the cache.
-     * If the digest was not found, Handler
-     * will be called with this signature:
-     *     SLE::const_pointer(void)
-     */
+    /** Fetch an item from the cache.
+        If the digest was not found, Handler
+        will be called with this signature:
+            SLE::const_pointer(void)
+    */
     template <class Handler>
     SharedPointerType
     fetch(key_type const& digest, Handler const& h);

include/xrpl/basics/TaggedCache.ipp

@@ -57,10 +57,7 @@ inline TaggedCache<
         beast::insight::Collector::ptr const& collector)
     : journal_(journal)
     , clock_(clock)
-    , stats_(
-          name,
-          [this] { collectMetrics(); },
-          collector)
+    , stats_(name, std::bind(&TaggedCache::collectMetrics, this), collector)
     , name_(name)
     , targetSize_(size)
     , targetAge_(expiration)
@@ -503,8 +500,7 @@ template <
 template <class ReturnType>
 inline auto
 TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash, KeyEqual, Mutex>::
-    insert(key_type const& key, T const& value) -> ReturnType
-    requires(!IsKeyCache)
+    insert(key_type const& key, T const& value) -> std::enable_if_t<!IsKeyCache, ReturnType>
 {
     static_assert(
         std::is_same_v<std::shared_ptr<T>, SharedPointerType> ||
@@ -534,8 +530,7 @@ template <
 template <class ReturnType>
 inline auto
 TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash, KeyEqual, Mutex>::
-    insert(key_type const& key) -> ReturnType
-    requires IsKeyCache
+    insert(key_type const& key) -> std::enable_if_t<IsKeyCache, ReturnType>
 {
     std::scoped_lock const lock(mutex_);
     clock_type::time_point const now(clock_.now());

include/xrpl/basics/ToString.h

@@ -5,17 +5,15 @@
 
 namespace xrpl {
 
-/**
- * to_string() generalizes std::to_string to handle bools, chars, and strings.
- *
- * It's also possible to provide implementation of to_string for a class
- * which needs a string implementation.
+/** to_string() generalizes std::to_string to handle bools, chars, and strings.
+
+    It's also possible to provide implementation of to_string for a class
+    which needs a string implementation.
  */
 
 template <class T>
-std::string
+std::enable_if_t<std::is_arithmetic_v<T>, std::string>
 to_string(T t)  // NOLINT(readability-identifier-naming)
-    requires(std::is_arithmetic_v<T>)
 {
     return std::to_string(t);
 }

include/xrpl/basics/UptimeClock.h

@@ -7,13 +7,12 @@
 
 namespace xrpl {
 
-/**
- * Tracks program uptime to seconds precision.
- *
- * The timer caches the current time as a performance optimization.
- * This allows clients to query the current time thousands of times
- * per second.
- */
+/** Tracks program uptime to seconds precision.
+
+    The timer caches the current time as a performance optimization.
+    This allows clients to query the current time thousands of times
+    per second.
+*/
 
 class UptimeClock
 {

include/xrpl/basics/base_uint.h

@@ -63,19 +63,18 @@ struct AlwaysFalseT : std::bool_constant<false>
 
 }  // namespace detail
 
-/**
- * Integers of any length that is a multiple of 32-bits
- *
- * @note This class stores its values internally in big-endian
- *       form and that internal representation is part of the
- *       binary protocol of the XRP Ledger and cannot be changed
- *       arbitrarily without causing breakage.
- *
- * @tparam Bits The number of bits this integer should have; must
- *              be at least 64 and a multiple of 32.
- * @tparam Tag An arbitrary type that functions as a tag and allows
- *             the instantiation of "distinct" types that the same
- *             number of bits.
+/** Integers of any length that is a multiple of 32-bits
+
+    @note This class stores its values internally in big-endian
+          form and that internal representation is part of the
+          binary protocol of the XRP Ledger and cannot be changed
+          arbitrarily without causing breakage.
+
+          @tparam Bits The number of bits this integer should have; must
+                       be at least 64 and a multiple of 32.
+          @tparam Tag An arbitrary type that functions as a tag and allows
+                      the instantiation of "distinct" types that the same
+                      number of bits.
  */
 template <std::size_t Bits, class Tag = void>
 class BaseUInt
@@ -98,7 +97,7 @@ public:
     //
 
     static constexpr std::size_t kBytes = Bits / 8;
-    static_assert(sizeof(data_) == kBytes);
+    static_assert(sizeof(data_) == kBytes, "");
 
     using size_type = std::size_t;
     using difference_type = std::ptrdiff_t;
@@ -155,23 +154,21 @@ public:
         return data() + kBytes;
     }
 
-    /**
-     * Value hashing function.
-     *  The seed prevents crafted inputs from causing degenerate parent
-     * containers.
-     */
+    /** Value hashing function.
+        The seed prevents crafted inputs from causing degenerate parent
+       containers.
+    */
     using hasher = HardenedHash<>;
 
     //--------------------------------------------------------------------------
 
 private:
-    /**
-     * Construct from a raw pointer.
-     * The buffer pointed to by `data` must be at least Bits/8 bytes.
-     *
-     * @note the structure is used to disambiguate this from the std::uint64_t
-     *       constructor: something like base_uint(0) is ambiguous.
-     */
+    /** Construct from a raw pointer.
+        The buffer pointed to by `data` must be at least Bits/8 bytes.
+
+        @note the structure is used to disambiguate this from the std::uint64_t
+              constructor: something like base_uint(0) is ambiguous.
+    */
     // NIKB TODO Remove the need for this constructor.
     struct VoidHelper
     {
@@ -283,11 +280,12 @@ public:
     {
     }
 
-    template <class Container>
-    explicit BaseUInt(Container const& c)
-        requires(
+    template <
+        class Container,
+        class = std::enable_if_t<
             detail::IsContiguousContainer<Container>::value &&
-            std::is_trivially_copyable_v<typename Container::value_type>)
+            std::is_trivially_copyable_v<typename Container::value_type>>>
+    explicit BaseUInt(Container const& c)
     {
         // Use AlwaysFalseT so the static_assert condition is dependent
         // and only triggers when this constructor template is instantiated.
@@ -297,12 +295,13 @@ public:
             "Use base_uint::fromRaw instead.");
     }
 
-    template <class Container>
+    template <
+        class Container,
+        class = std::enable_if_t<
+            detail::IsContiguousContainer<Container>::value &&
+            std::is_trivially_copyable_v<typename Container::value_type>>>
     static BaseUInt
     fromRaw(Container const& c)
-        requires(
-            detail::IsContiguousContainer<Container>::value &&
-            std::is_trivially_copyable_v<typename Container::value_type>)
     {
         BaseUInt result;
         XRPL_ASSERT(
@@ -313,11 +312,11 @@ public:
     }
 
     template <class Container>
-    BaseUInt&
+    std::enable_if_t<
+        detail::IsContiguousContainer<Container>::value &&
+            std::is_trivially_copyable_v<typename Container::value_type>,
+        BaseUInt&>
     operator=(Container const& c)
-        requires(
-            detail::IsContiguousContainer<Container>::value &&
-            std::is_trivially_copyable_v<typename Container::value_type>)
     {
         XRPL_ASSERT(
             c.size() * sizeof(typename Container::value_type) == size(),
@@ -506,14 +505,13 @@ public:
         h(a.data_.data(), sizeof(a.data_));
     }
 
-    /**
-     * Parse a hex string into a base_uint
-     *
-     * The input must be precisely `2 * bytes` hexadecimal characters
-     * long, with one exception: the value '0'.
-     *
-     * @param sv A null-terminated string of hexadecimal characters
-     * @return true if the input was parsed properly; false otherwise.
+    /** Parse a hex string into a base_uint
+
+        The input must be precisely `2 * bytes` hexadecimal characters
+        long, with one exception: the value '0'.
+
+        @param sv A null-terminated string of hexadecimal characters
+        @return true if the input was parsed properly; false otherwise.
      */
     [[nodiscard]] constexpr bool
     parseHex(std::string_view sv)
@@ -599,7 +597,7 @@ template <std::size_t Bits, typename Tag>
 [[nodiscard]] constexpr bool
 operator==(BaseUInt<Bits, Tag> const& lhs, BaseUInt<Bits, Tag> const& rhs)
 {
-    return (lhs <=> rhs) == 0;  // NOLINT(modernize-use-nullptr)
+    return (lhs <=> rhs) == 0;
 }
 
 //------------------------------------------------------------------------------

include/xrpl/basics/chrono.h

@@ -21,16 +21,15 @@ using days =
 
 using weeks = std::chrono::duration<int, std::ratio_multiply<days::period, std::ratio<7>>>;
 
-/**
- * Clock for measuring the network time.
- *
- * The epoch is January 1, 2000
- *
- * epoch_offset
- * = date(2000-01-01) - date(1970-0-01)
- * = days(10957)
- * = seconds(946684800)
- */
+/** Clock for measuring the network time.
+
+    The epoch is January 1, 2000
+
+    epoch_offset
+    = date(2000-01-01) - date(1970-0-01)
+    = days(10957)
+    = seconds(946684800)
+*/
 
 static constexpr std::chrono::seconds kEpochOffset =
     date::sys_days{date::year{2000} / 1 / 1} - date::sys_days{date::year{1970} / 1 / 1};
@@ -82,21 +81,16 @@ toStringIso(NetClock::time_point tp)
     return toStringIso(date::sys_time<NetClock::duration>{tp.time_since_epoch() + kEpochOffset});
 }
 
-/**
- * A clock for measuring elapsed time.
- *
- * The epoch is unspecified.
- */
+/** A clock for measuring elapsed time.
+
+    The epoch is unspecified.
+*/
 using Stopwatch = beast::AbstractClock<std::chrono::steady_clock>;
 
-/**
- * A manual Stopwatch for unit tests.
- */
+/** A manual Stopwatch for unit tests. */
 using TestStopwatch = beast::ManualClock<std::chrono::steady_clock>;
 
-/**
- * Returns an instance of a wall clock.
- */
+/** Returns an instance of a wall clock. */
 inline Stopwatch&
 stopwatch()
 {

include/xrpl/basics/comparators.h

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <functional>
+
+namespace xrpl {
+
+#ifdef _MSC_VER
+
+/*
+ * MSVC 2019 version 16.9.0 added [[nodiscard]] to the std comparison
+ * operator() functions. boost::bimap checks that the comparator is a
+ * BinaryFunction, in part by calling the function and ignoring the value.
+ * These two things don't play well together. These wrapper classes simply
+ * strip [[nodiscard]] from operator() for use in boost::bimap.
+ *
+ * See also:
+ *  https://www.boost.org/doc/libs/1_75_0/libs/bimap/doc/html/boost_bimap/the_tutorial/controlling_collection_types.html
+ */
+
+template <class T = void>
+struct less
+{
+    using result_type = bool;
+
+    constexpr bool
+    operator()(T const& left, T const& right) const
+    {
+        return std::less<T>()(left, right);
+    }
+};
+
+template <class T = void>
+struct equal_to
+{
+    using result_type = bool;
+
+    constexpr bool
+    operator()(T const& left, T const& right) const
+    {
+        return std::equal_to<T>()(left, right);
+    }
+};
+
+#else
+
+template <class T = void>
+using less = std::less<T>;
+
+template <class T = void>
+using equal_to = std::equal_to<T>;
+
+#endif
+
+}  // namespace xrpl

include/xrpl/basics/contract.h

@@ -15,23 +15,20 @@ namespace xrpl {
     preconditions, postconditions, and invariants.
 */
 
-/**
- * Generates and logs a call stack
- */
+/** Generates and logs a call stack */
 void
 logThrow(std::string const& title);
 
-/**
- * Rethrow the exception currently being handled.
- *
- * When called from within a catch block, it will pass
- * control to the next matching exception handler, if any.
- * Otherwise, std::terminate will be called.
- *
- * ASAN can't handle sudden jumps in control flow very well. This
- * function is marked as XRPL_NO_SANITIZE_ADDRESS to prevent it from
- * triggering false positives, since it throws.
- */
+/** Rethrow the exception currently being handled.
+
+    When called from within a catch block, it will pass
+    control to the next matching exception handler, if any.
+    Otherwise, std::terminate will be called.
+
+    ASAN can't handle sudden jumps in control flow very well. This
+    function is marked as XRPL_NO_SANITIZE_ADDRESS to prevent it from
+    triggering false positives, since it throws.
+*/
 [[noreturn]] XRPL_NO_SANITIZE_ADDRESS inline void
 rethrow()
 {
@@ -59,9 +56,7 @@ Throw(Args&&... args)
     throw std::move(e);
 }
 
-/**
- * Called when faulty logic causes a broken invariant.
- */
+/** Called when faulty logic causes a broken invariant. */
 [[noreturn]] void
 logicError(std::string const& how) noexcept;
 

include/xrpl/basics/hardened_hash.h

@@ -39,33 +39,33 @@ makeSeedPair() noexcept
 
 /**
  * Seed functor once per construction
- *
- * A std compatible hash adapter that resists adversarial inputs.
- * For this to work, T must implement in its own namespace:
- *
- * @code
- *
- * template <class Hasher>
- * void
- * hash_append (Hasher& h, T const& t) noexcept
- * {
- *     // hash_append each base and member that should
- *     //  participate in forming the hash
- *     using beast::hash_append;
- *     hash_append (h, static_cast<T::base1 const&>(t));
- *     hash_append (h, static_cast<T::base2 const&>(t));
- *     // ...
- *     hash_append (h, t.member1);
- *     hash_append (h, t.member2);
- *     // ...
- * }
- *
- * @endcode
- *
- * Do not use any version of Murmur or CityHash for the Hasher
- * template parameter (the hashing algorithm).  For details
- * see https://131002.net/siphash/#at
- */
+
+   A std compatible hash adapter that resists adversarial inputs.
+   For this to work, T must implement in its own namespace:
+
+   @code
+
+   template <class Hasher>
+   void
+   hash_append (Hasher& h, T const& t) noexcept
+   {
+       // hash_append each base and member that should
+       //  participate in forming the hash
+       using beast::hash_append;
+       hash_append (h, static_cast<T::base1 const&>(t));
+       hash_append (h, static_cast<T::base2 const&>(t));
+       // ...
+       hash_append (h, t.member1);
+       hash_append (h, t.member2);
+       // ...
+   }
+
+   @endcode
+
+   Do not use any version of Murmur or CityHash for the Hasher
+   template parameter (the hashing algorithm).  For details
+   see https://131002.net/siphash/#at
+*/
 
 template <class HashAlgorithm = beast::Xxhasher>
 class HardenedHash

include/xrpl/basics/make_SSLContext.h

@@ -7,15 +7,11 @@
 
 namespace xrpl {
 
-/**
- * Create a self-signed SSL context that allows anonymous Diffie Hellman.
- */
+/** Create a self-signed SSL context that allows anonymous Diffie Hellman. */
 std::shared_ptr<boost::asio::ssl::context>
 makeSslContext(std::string const& cipherList);
 
-/**
- * Create an authenticated SSL context using the specified files.
- */
+/** Create an authenticated SSL context using the specified files. */
 std::shared_ptr<boost::asio::ssl::context>
 makeSslContextAuthed(
     std::string const& keyFile,

include/xrpl/basics/mulDiv.h

@@ -7,16 +7,16 @@
 namespace xrpl {
 constexpr auto kMuldivMax = std::numeric_limits<std::uint64_t>::max();
 
-/**
- * Return value*mul/div accurately.
- *
- * Computes the result of the multiplication and division in
- * a single step, avoiding overflow and retaining precision.
- *
- * @throws None
- * @return `std::nullopt` if the calculation overflows. Otherwise,
- *         `value * mul / div`.
- */
+/** Return value*mul/div accurately.
+    Computes the result of the multiplication and division in
+    a single step, avoiding overflow and retaining precision.
+    Throws:
+        None
+    Returns:
+        `std::optional`:
+            `std::nullopt` if the calculation overflows. Otherwise, `value * mul
+   / div`.
+*/
 std::optional<std::uint64_t>
 mulDiv(std::uint64_t value, std::uint64_t mul, std::uint64_t div);
 

include/xrpl/basics/partitioned_unordered_map.h

@@ -138,8 +138,11 @@ public:
         {
         }
 
-        ConstIterator(Iterator const& orig) : map(orig.map), ait(orig.ait), mit(orig.mit)
+        ConstIterator(Iterator const& orig)
         {
+            map = orig.map;
+            ait = orig.ait;
+            mit = orig.mit;
         }
 
         const_reference
@@ -228,11 +231,11 @@ private:
 
 public:
     PartitionedUnorderedMap(std::optional<std::size_t> partitions = std::nullopt)
+    {
         // Set partitions to the number of hardware threads if the parameter
         // is either empty or set to 0.
-        : partitions_(
-              partitions && (*partitions != 0u) ? *partitions : std::thread::hardware_concurrency())
-    {
+        partitions_ =
+            partitions && (*partitions != 0u) ? *partitions : std::thread::hardware_concurrency();
         map_.resize(partitions_);
         XRPL_ASSERT(
             partitions_,

include/xrpl/basics/random.h

@@ -33,17 +33,16 @@ template <class Engine, class Result = typename Engine::result_type>
 using is_engine = std::is_invocable_r<Result, Engine>;
 }  // namespace detail
 
-/**
- * Return the default random engine.
- *
- * This engine is guaranteed to be deterministic, but by
- * default will be randomly seeded. It is NOT cryptographically
- * secure and MUST NOT be used to generate randomness that
- * will be used for keys, secure cookies, IVs, padding, etc.
- *
- * Each thread gets its own instance of the engine which
- * will be randomly seeded.
- */
+/** Return the default random engine.
+
+    This engine is guaranteed to be deterministic, but by
+    default will be randomly seeded. It is NOT cryptographically
+    secure and MUST NOT be used to generate randomness that
+    will be used for keys, secure cookies, IVs, padding, etc.
+
+    Each thread gets its own instance of the engine which
+    will be randomly seeded.
+*/
 inline beast::xor_shift_engine&
 defaultPrng()
 {
@@ -71,31 +70,29 @@ defaultPrng()
     return kEngine;
 }
 
-/**
- * Return a uniformly distributed random integer.
- *
- * @param min The smallest value to return. If not specified
- *            the value defaults to 0.
- * @param max The largest value to return. If not specified
- *            the value defaults to the largest value that
- *            can be represented.
- *
- * The randomness is generated by the specified engine (or
- * the default engine if one is not specified). The result
- * is cryptographically secure only when the engine passed
- * into the function is cryptographically secure.
- *
- * @note The range is always a closed interval, so calling
- *       rand_int(-5, 15) can return any integer in the
- *       closed interval [-5, 15]; similarly, calling
- *       rand_int(7) can return any integer in the closed
- *       interval [0, 7].
- */
+/** Return a uniformly distributed random integer.
+
+    @param min The smallest value to return. If not specified
+               the value defaults to 0.
+    @param max The largest value to return. If not specified
+               the value defaults to the largest value that
+               can be represented.
+
+    The randomness is generated by the specified engine (or
+    the default engine if one is not specified). The result
+    is cryptographically secure only when the engine passed
+    into the function is cryptographically secure.
+
+    @note The range is always a closed interval, so calling
+          rand_int(-5, 15) can return any integer in the
+          closed interval [-5, 15]; similarly, calling
+          rand_int(7) can return any integer in the closed
+          interval [0, 7].
+*/
 /** @{ */
 template <class Engine, class Integral>
-Integral
+std::enable_if_t<std::is_integral_v<Integral> && detail::is_engine<Engine>::value, Integral>
 randInt(Engine& engine, Integral min, Integral max)
-    requires(std::is_integral_v<Integral> && detail::is_engine<Engine>::value)
 {
     XRPL_ASSERT(max > min, "xrpl::randInt : max over min inputs");
 
@@ -106,73 +103,63 @@ randInt(Engine& engine, Integral min, Integral max)
 }
 
 template <class Integral>
-Integral
+std::enable_if_t<std::is_integral_v<Integral>, Integral>
 randInt(Integral min, Integral max)
-    requires(std::is_integral_v<Integral>)
 {
     return randInt(defaultPrng(), min, max);
 }
 
 template <class Engine, class Integral>
-Integral
+std::enable_if_t<std::is_integral_v<Integral> && detail::is_engine<Engine>::value, Integral>
 randInt(Engine& engine, Integral max)
-    requires(std::is_integral_v<Integral> && detail::is_engine<Engine>::value)
 {
     return randInt(engine, Integral(0), max);
 }
 
 template <class Integral>
-Integral
+std::enable_if_t<std::is_integral_v<Integral>, Integral>
 randInt(Integral max)
-    requires(std::is_integral_v<Integral>)
 {
     return randInt(defaultPrng(), max);
 }
 
 template <class Integral, class Engine>
-Integral
+std::enable_if_t<std::is_integral_v<Integral> && detail::is_engine<Engine>::value, Integral>
 randInt(Engine& engine)
-    requires(std::is_integral_v<Integral> && detail::is_engine<Engine>::value)
 {
     return randInt(engine, std::numeric_limits<Integral>::max());
 }
 
 template <class Integral = int>
-Integral
+std::enable_if_t<std::is_integral_v<Integral>, Integral>
 randInt()
-    requires(std::is_integral_v<Integral>)
 {
     return randInt(defaultPrng(), std::numeric_limits<Integral>::max());
 }
 /** @} */
 
-/**
- * Return a random byte
- */
+/** Return a random byte */
 /** @{ */
 template <class Byte, class Engine>
-Byte
+std::enable_if_t<
+    (std::is_same_v<Byte, unsigned char> || std::is_same_v<Byte, std::uint8_t>) &&
+        detail::is_engine<Engine>::value,
+    Byte>
 randByte(Engine& engine)
-    requires(
-        (std::is_same_v<Byte, unsigned char> || std::is_same_v<Byte, std::uint8_t>) &&
-        detail::is_engine<Engine>::value)
 {
     return static_cast<Byte>(randInt<Engine, std::uint32_t>(
         engine, std::numeric_limits<Byte>::min(), std::numeric_limits<Byte>::max()));
 }
 
 template <class Byte = std::uint8_t>
-Byte
+std::enable_if_t<(std::is_same_v<Byte, unsigned char> || std::is_same_v<Byte, std::uint8_t>), Byte>
 randByte()
-    requires(std::is_same_v<Byte, unsigned char> || std::is_same_v<Byte, std::uint8_t>)
 {
     return randByte<Byte>(defaultPrng());
 }
 /** @} */
 
-/**
- * Return a random boolean value
- */
+/** Return a random boolean value */
 /** @{ */
 template <class Engine>
 inline bool

include/xrpl/basics/safe_cast.h

@@ -1,7 +1,5 @@
 #pragma once
 
-#include <xrpl/beast/utility/instrumentation.h>  // IWYU pragma: keep
-
 #include <type_traits>
 
 namespace xrpl {
@@ -17,9 +15,8 @@ concept SafeToCast = (std::is_integral_v<Src> && std::is_integral_v<Dest>) &&
                                                      : sizeof(Dest) >= sizeof(Src));
 
 template <class Dest, class Src>
-constexpr Dest
+constexpr std::enable_if_t<std::is_integral_v<Dest> && std::is_integral_v<Src>, Dest>
 safeCast(Src s) noexcept
-    requires(std::is_integral_v<Dest> && std::is_integral_v<Src>)
 {
     static_assert(
         std::is_signed_v<Dest> || std::is_unsigned_v<Src>, "Cannot cast signed to unsigned");
@@ -31,17 +28,15 @@ safeCast(Src s) noexcept
 }
 
 template <class Dest, class Src>
-constexpr Dest
+constexpr std::enable_if_t<std::is_enum_v<Dest> && std::is_integral_v<Src>, Dest>
 safeCast(Src s) noexcept
-    requires(std::is_enum_v<Dest> && std::is_integral_v<Src>)
 {
     return static_cast<Dest>(safeCast<std::underlying_type_t<Dest>>(s));
 }
 
 template <class Dest, class Src>
-constexpr Dest
+constexpr std::enable_if_t<std::is_integral_v<Dest> && std::is_enum_v<Src>, Dest>
 safeCast(Src s) noexcept
-    requires(std::is_integral_v<Dest> && std::is_enum_v<Src>)
 {
     return safeCast<Dest>(static_cast<std::underlying_type_t<Src>>(s));
 }
@@ -51,9 +46,8 @@ safeCast(Src s) noexcept
 // underlying types become safe, it can be converted to a safe_cast.
 
 template <class Dest, class Src>
-constexpr Dest
+constexpr std::enable_if_t<std::is_integral_v<Dest> && std::is_integral_v<Src>, Dest>
 unsafeCast(Src s) noexcept
-    requires(std::is_integral_v<Dest> && std::is_integral_v<Src>)
 {
     static_assert(
         !SafeToCast<Src, Dest>,
@@ -63,17 +57,15 @@ unsafeCast(Src s) noexcept
 }
 
 template <class Dest, class Src>
-constexpr Dest
+constexpr std::enable_if_t<std::is_enum_v<Dest> && std::is_integral_v<Src>, Dest>
 unsafeCast(Src s) noexcept
-    requires(std::is_enum_v<Dest> && std::is_integral_v<Src>)
 {
     return static_cast<Dest>(unsafeCast<std::underlying_type_t<Dest>>(s));
 }
 
 template <class Dest, class Src>
-constexpr Dest
+constexpr std::enable_if_t<std::is_integral_v<Dest> && std::is_enum_v<Src>, Dest>
 unsafeCast(Src s) noexcept
-    requires(std::is_integral_v<Dest> && std::is_enum_v<Src>)
 {
     return unsafeCast<Dest>(static_cast<std::underlying_type_t<Src>>(s));
 }

include/xrpl/basics/scope.h

@@ -46,9 +46,11 @@ public:
     operator=(ScopeExit&&) = delete;
 
     template <class EFP>
-    explicit ScopeExit(EFP&& f) noexcept
-        requires(
-            !std::is_same_v<std::remove_cv_t<EFP>, ScopeExit> && std::is_constructible_v<EF, EFP>)
+    explicit ScopeExit(
+        EFP&& f,
+        std::enable_if_t<
+            !std::is_same_v<std::remove_cv_t<EFP>, ScopeExit> &&
+            std::is_constructible_v<EF, EFP>>* = 0) noexcept
         : exitFunction_{std::forward<EFP>(f)}
     {
         static_assert(std::is_nothrow_constructible_v<EF, decltype(std::forward<EFP>(f))>);
@@ -91,9 +93,11 @@ public:
     operator=(ScopeFail&&) = delete;
 
     template <class EFP>
-    explicit ScopeFail(EFP&& f) noexcept
-        requires(
-            !std::is_same_v<std::remove_cv_t<EFP>, ScopeFail> && std::is_constructible_v<EF, EFP>)
+    explicit ScopeFail(
+        EFP&& f,
+        std::enable_if_t<
+            !std::is_same_v<std::remove_cv_t<EFP>, ScopeFail> &&
+            std::is_constructible_v<EF, EFP>>* = 0) noexcept
         : exitFunction_{std::forward<EFP>(f)}
     {
         static_assert(std::is_nothrow_constructible_v<EF, decltype(std::forward<EFP>(f))>);
@@ -136,11 +140,12 @@ public:
     operator=(ScopeSuccess&&) = delete;
 
     template <class EFP>
-    explicit ScopeSuccess(EFP&& f) noexcept(
-        std::is_nothrow_constructible_v<EF, EFP> || std::is_nothrow_constructible_v<EF, EFP&>)
-        requires(
+    explicit ScopeSuccess(
+        EFP&& f,
+        std::enable_if_t<
             !std::is_same_v<std::remove_cv_t<EFP>, ScopeSuccess> &&
-            std::is_constructible_v<EF, EFP>)
+            std::is_constructible_v<EF, EFP>>* =
+            0) noexcept(std::is_nothrow_constructible_v<EF, EFP> || std::is_nothrow_constructible_v<EF, EFP&>)
         : exitFunction_{std::forward<EFP>(f)}
     {
     }
@@ -156,41 +161,41 @@ template <class EF>
 ScopeSuccess(EF) -> ScopeSuccess<EF>;
 
 /**
- * Automatically unlocks and re-locks a unique_lock object.
- *
- * This is the reverse of a std::unique_lock object - instead of locking the
- * mutex for the lifetime of this object, it unlocks it.
- *
- * Make sure you don't try to unlock mutexes that aren't actually locked!
- *
- * This is essentially a less-versatile boost::reverse_lock.
- *
- * e.g. @code
- *
- * std::mutex mut;
- *
- * for (;;)
- * {
- *     std::unique_lock myScopedLock{mut};
- *     // mut is now locked
- *
- *     ... do some stuff with it locked ..
- *
- *     while (xyz)
- *     {
- *         ... do some stuff with it locked ..
- *
- *         scope_unlock unlocker{myScopedLock};
- *
- *         // mut is now unlocked for the remainder of this block,
- *         // and re-locked at the end.
- *
- *         ...do some stuff with it unlocked ...
- *     }  // mut gets locked here.
- *
- * }  // mut gets unlocked here
- * @endcode
- */
+    Automatically unlocks and re-locks a unique_lock object.
+
+    This is the reverse of a std::unique_lock object - instead of locking the
+   mutex for the lifetime of this object, it unlocks it.
+
+    Make sure you don't try to unlock mutexes that aren't actually locked!
+
+    This is essentially a less-versatile boost::reverse_lock.
+
+    e.g. @code
+
+    std::mutex mut;
+
+    for (;;)
+    {
+        std::unique_lock myScopedLock{mut};
+        // mut is now locked
+
+        ... do some stuff with it locked ..
+
+        while (xyz)
+        {
+            ... do some stuff with it locked ..
+
+            scope_unlock unlocker{myScopedLock};
+
+            // mut is now unlocked for the remainder of this block,
+            // and re-locked at the end.
+
+            ...do some stuff with it unlocked ...
+        }  // mut gets locked here.
+
+    }  // mut gets unlocked here
+    @endcode
+*/
 
 template <class Mutex>
 class ScopeUnlock

include/xrpl/basics/spinlock.h

@@ -15,16 +15,15 @@
 namespace xrpl {
 
 namespace detail {
-/**
- * Inform the processor that we are in a tight spin-wait loop.
- *
- * Spinlocks caught in tight loops can result in the processor's pipeline
- * filling up with comparison operations, resulting in a misprediction at
- * the time the lock is finally acquired, necessitating pipeline flushing
- * which is ridiculously expensive and results in very high latency.
- *
- * This function instructs the processor to "pause" for some architecture
- * specific amount of time, to prevent this.
+/** Inform the processor that we are in a tight spin-wait loop.
+
+    Spinlocks caught in tight loops can result in the processor's pipeline
+    filling up with comparison operations, resulting in a misprediction at
+    the time the lock is finally acquired, necessitating pipeline flushing
+    which is ridiculously expensive and results in very high latency.
+
+    This function instructs the processor to "pause" for some architecture
+    specific amount of time, to prevent this.
  */
 inline void
 spinPause() noexcept
@@ -39,39 +38,37 @@ spinPause() noexcept
 }  // namespace detail
 
 /** @{ */
-/**
- * Classes to handle arrays of spinlocks packed into a single atomic integer:
- *
- * Packed spinlocks allow for tremendously space-efficient lock-sharding
- * but they come at a cost.
- *
- * First, the implementation is necessarily low-level and uses advanced
- * features like memory ordering and highly platform-specific tricks to
- * maximize performance. This imposes a significant and ongoing cost to
- * developers.
- *
- * Second, and perhaps most important, is that the packing of multiple
- * locks into a single integer which, albeit space-efficient, also has
- * performance implications stemming from data dependencies, increased
- * cache-coherency traffic between processors and heavier loads on the
- * processor's load/store units.
- *
- * To be sure, these locks can have advantages but they are definitely
- * not general purpose locks and should not be thought of or used that
- * way. The use cases for them are likely few and far between; without
- * a compelling reason to use them, backed by profiling data, it might
- * be best to use one of the standard locking primitives instead. Note
- * that in most common platforms, `std::mutex` is so heavily optimized
- * that it can, usually, outperform spinlocks.
- *
- * @tparam T An unsigned integral type (e.g. std::uint16_t)
+/** Classes to handle arrays of spinlocks packed into a single atomic integer:
+
+    Packed spinlocks allow for tremendously space-efficient lock-sharding
+    but they come at a cost.
+
+    First, the implementation is necessarily low-level and uses advanced
+    features like memory ordering and highly platform-specific tricks to
+    maximize performance. This imposes a significant and ongoing cost to
+    developers.
+
+    Second, and perhaps most important, is that the packing of multiple
+    locks into a single integer which, albeit space-efficient, also has
+    performance implications stemming from data dependencies, increased
+    cache-coherency traffic between processors and heavier loads on the
+    processor's load/store units.
+
+    To be sure, these locks can have advantages but they are definitely
+    not general purpose locks and should not be thought of or used that
+    way. The use cases for them are likely few and far between; without
+    a compelling reason to use them, backed by profiling data, it might
+    be best to use one of the standard locking primitives instead. Note
+    that in most common platforms, `std::mutex` is so heavily optimized
+    that it can, usually, outperform spinlocks.
+
+    @tparam T An unsigned integral type (e.g. std::uint16_t)
  */
 
-/**
- * A class that grabs a single packed spinlock from an atomic integer.
- *
- * This class meets the requirements of Lockable:
- *     https://en.cppreference.com/w/cpp/named_req/Lockable
+/** A class that grabs a single packed spinlock from an atomic integer.
+
+    This class meets the requirements of Lockable:
+        https://en.cppreference.com/w/cpp/named_req/Lockable
  */
 template <class T>
 class PackedSpinlock
@@ -94,14 +91,13 @@ public:
     PackedSpinlock&
     operator=(PackedSpinlock const&) = delete;
 
-    /**
-     * A single spinlock packed inside the specified atomic
-     *
-     * @param lock The atomic integer inside which the spinlock is packed.
-     * @param index The index of the spinlock this object acquires.
-     *
-     * @note For performance reasons, you should strive to have `lock` be
-     *       on a cacheline by itself.
+    /** A single spinlock packed inside the specified atomic
+
+        @param lock The atomic integer inside which the spinlock is packed.
+        @param index The index of the spinlock this object acquires.
+
+        @note For performance reasons, you should strive to have `lock` be
+              on a cacheline by itself.
      */
     PackedSpinlock(std::atomic<T>& lock, int index) : bits_(lock), mask_(static_cast<T>(1) << index)
     {
@@ -137,18 +133,17 @@ public:
     }
 };
 
-/**
- * A spinlock implemented on top of an atomic integer.
- *
- * @note Using `packed_spinlock` and `spinlock` against the same underlying
- *       atomic integer can result in `spinlock` not being able to actually
- *       acquire the lock during periods of high contention, because of how
- *       the two locks operate: `spinlock` will spin trying to grab all the
- *       bits at once, whereas any given `packed_spinlock` will only try to
- *       grab one bit at a time. Caveat emptor.
- *
- * This class meets the requirements of Lockable:
- *     https://en.cppreference.com/w/cpp/named_req/Lockable
+/** A spinlock implemented on top of an atomic integer.
+
+    @note Using `packed_spinlock` and `spinlock` against the same underlying
+          atomic integer can result in `spinlock` not being able to actually
+          acquire the lock during periods of high contention, because of how
+          the two locks operate: `spinlock` will spin trying to grab all the
+          bits at once, whereas any given `packed_spinlock` will only try to
+          grab one bit at a time. Caveat emptor.
+
+    This class meets the requirements of Lockable:
+        https://en.cppreference.com/w/cpp/named_req/Lockable
  */
 template <class T>
 class Spinlock
@@ -164,13 +159,12 @@ public:
     Spinlock&
     operator=(Spinlock const&) = delete;
 
-    /**
-     * Grabs the
-     *
-     * @param lock The atomic integer to spin against.
-     *
-     * @note For performance reasons, you should strive to have `lock` be
-     *       on a cacheline by itself.
+    /** Grabs the
+
+        @param lock The atomic integer to spin against.
+
+        @note For performance reasons, you should strive to have `lock` be
+              on a cacheline by itself.
      */
     Spinlock(std::atomic<T>& lock) : lock_(lock)
     {

include/xrpl/basics/tagged_integer.h

@@ -12,18 +12,17 @@
 
 namespace xrpl {
 
-/**
- * A type-safe wrap around standard integral types
- *
- * The tag is used to implement type safety, catching mismatched types at
- * compile time. Multiple instantiations wrapping the same underlying integral
- * type are distinct types (distinguished by tag) and will not interoperate. A
- * tagged_integer supports all the usual assignment, arithmetic, comparison and
- * shifting operations defined for the underlying type
- *
- * The tag is not meant as a unit, which would require restricting the set of
- * allowed arithmetic operations.
- */
+/** A type-safe wrap around standard integral types
+
+    The tag is used to implement type safety, catching mismatched types at
+    compile time. Multiple instantiations wrapping the same underlying integral
+    type are distinct types (distinguished by tag) and will not interoperate. A
+    tagged_integer supports all the usual assignment, arithmetic, comparison and
+    shifting operations defined for the underlying type
+
+    The tag is not meant as a unit, which would require restricting the set of
+    allowed arithmetic operations.
+*/
 template <class Int, class Tag>
 class TaggedInteger : boost::totally_ordered<
                           TaggedInteger<Int, Tag>,
@@ -44,10 +43,10 @@ public:
 
     TaggedInteger() = default;
 
-    template <class OtherInt>
-    explicit constexpr TaggedInteger(OtherInt value) noexcept
-        requires(std::is_integral_v<OtherInt> && sizeof(OtherInt) <= sizeof(Int))
-        : value_(value)
+    template <
+        class OtherInt,
+        class = std::enable_if_t<std::is_integral_v<OtherInt> && sizeof(OtherInt) <= sizeof(Int)>>
+    explicit constexpr TaggedInteger(OtherInt value) noexcept : value_(value)
     {
         static_assert(sizeof(TaggedInteger) == sizeof(Int), "tagged_integer is adding padding");
     }

include/xrpl/beast/asio/io_latency_probe.h

@@ -14,9 +14,7 @@
 
 namespace beast {
 
-/**
- * Measures handler latency on an io_context queue.
- */
+/** Measures handler latency on an io_context queue. */
 template <class Clock>
 class IOLatencyProbe
 {
@@ -44,9 +42,7 @@ public:
         cancel(lock, true);
     }
 
-    /**
-     * Return the io_context associated with the latency probe.
-     */
+    /** Return the io_context associated with the latency probe. */
     /** @{ */
     boost::asio::io_context&
     getIoContext()
@@ -61,10 +57,9 @@ public:
     }
     /** @} */
 
-    /**
-     * Cancel all pending i/o.
-     * Any handlers which have already been queued will still be called.
-     */
+    /** Cancel all pending i/o.
+        Any handlers which have already been queued will still be called.
+    */
     /** @{ */
     void
     cancel()
@@ -81,11 +76,10 @@ public:
     }
     /** @} */
 
-    /**
-     * Measure one sample of i/o latency.
-     * Handler will be called with this signature:
-     *     void Handler (Duration d);
-     */
+    /** Measure one sample of i/o latency.
+        Handler will be called with this signature:
+            void Handler (Duration d);
+    */
     template <class Handler>
     void
     sampleOne(Handler&& handler)
@@ -97,11 +91,10 @@ public:
             ios_, SampleOp<Handler>(std::forward<Handler>(handler), Clock::now(), false, this));
     }
 
-    /**
-     * Initiate continuous i/o latency sampling.
-     * Handler will be called with this signature:
-     *     void Handler (std::chrono::milliseconds);
-     */
+    /** Initiate continuous i/o latency sampling.
+        Handler will be called with this signature:
+            void Handler (std::chrono::milliseconds);
+    */
     template <class Handler>
     void
     sample(Handler&& handler)

include/xrpl/beast/clock/abstract_clock.h

@@ -2,35 +2,34 @@
 
 namespace beast {
 
-/**
- * Abstract interface to a clock.
- *
- * This makes now() a member function instead of a static member, so
- * an instance of the class can be dependency injected, facilitating
- * unit tests where time may be controlled.
- *
- * An abstract_clock inherits all the nested types of the Clock
- * template parameter.
- *
- * Example:
- *
- * @code
- *
- * struct Implementation
- * {
- *     using clock_type = abstract_clock <std::chrono::steady_clock>;
- *     clock_type& clock_;
- *     explicit Implementation (clock_type& clock)
- *         : clock_(clock)
- *     {
- *     }
- * };
- *
- * @endcode
- *
- * @tparam Clock A type meeting these requirements:
- *     http://en.cppreference.com/w/cpp/concept/Clock
- */
+/** Abstract interface to a clock.
+
+    This makes now() a member function instead of a static member, so
+    an instance of the class can be dependency injected, facilitating
+    unit tests where time may be controlled.
+
+    An abstract_clock inherits all the nested types of the Clock
+    template parameter.
+
+    Example:
+
+    @code
+
+    struct Implementation
+    {
+        using clock_type = abstract_clock <std::chrono::steady_clock>;
+        clock_type& clock_;
+        explicit Implementation (clock_type& clock)
+            : clock_(clock)
+        {
+        }
+    };
+
+    @endcode
+
+    @tparam Clock A type meeting these requirements:
+        http://en.cppreference.com/w/cpp/concept/Clock
+*/
 template <class Clock>
 class AbstractClock
 {
@@ -47,9 +46,7 @@ public:
     AbstractClock() = default;
     AbstractClock(AbstractClock const&) = default;
 
-    /**
-     * Returns the current time.
-     */
+    /** Returns the current time. */
     [[nodiscard]] virtual time_point
     now() const = 0;
 };
@@ -77,12 +74,11 @@ struct AbstractClockWrapper : public AbstractClock<Facade>
 
 //------------------------------------------------------------------------------
 
-/**
- * Returns a global instance of an abstract clock.
- * @tparam Facade A type meeting these requirements:
- *     http://en.cppreference.com/w/cpp/concept/Clock
- * @tparam Clock The actual concrete clock to use.
- */
+/** Returns a global instance of an abstract clock.
+    @tparam Facade A type meeting these requirements:
+        http://en.cppreference.com/w/cpp/concept/Clock
+    @tparam Clock The actual concrete clock to use.
+*/
 template <class Facade, class Clock = Facade>
 AbstractClock<Facade>&
 getAbstractClock()

include/xrpl/beast/clock/basic_seconds_clock.h

@@ -4,16 +4,15 @@
 
 namespace beast {
 
-/**
- * A clock whose minimum resolution is one second.
- *
- * The purpose of this class is to optimize the performance of the now()
- * member function call. It uses a dedicated thread that wakes up at least
- * once per second to sample the requested trivial clock.
- *
- * @tparam Clock A type meeting these requirements:
- *     http://en.cppreference.com/w/cpp/concept/Clock
- */
+/** A clock whose minimum resolution is one second.
+
+    The purpose of this class is to optimize the performance of the now()
+    member function call. It uses a dedicated thread that wakes up at least
+    once per second to sample the requested trivial clock.
+
+    @tparam Clock A type meeting these requirements:
+        http://en.cppreference.com/w/cpp/concept/Clock
+*/
 class BasicSecondsClock
 {
 public:

include/xrpl/beast/clock/manual_clock.h

@@ -7,16 +7,15 @@
 
 namespace beast {
 
-/**
- * Manual clock implementation.
- *
- * This concrete class implements the @ref abstract_clock interface and
- * allows the time to be advanced manually, mainly for the purpose of
- * providing a clock in unit tests.
- *
- * @tparam Clock A type meeting these requirements:
- *     http://en.cppreference.com/w/cpp/concept/Clock
- */
+/** Manual clock implementation.
+
+    This concrete class implements the @ref abstract_clock interface and
+    allows the time to be advanced manually, mainly for the purpose of
+    providing a clock in unit tests.
+
+    @tparam Clock A type meeting these requirements:
+        http://en.cppreference.com/w/cpp/concept/Clock
+*/
 template <class Clock>
 class ManualClock : public AbstractClock<Clock>
 {
@@ -39,9 +38,7 @@ public:
         return now_;
     }
 
-    /**
-     * Set the current time of the manual clock.
-     */
+    /** Set the current time of the manual clock. */
     void
     set(time_point const& when)
     {
@@ -51,9 +48,7 @@ public:
         now_ = when;
     }
 
-    /**
-     * Convenience for setting the time in seconds from epoch.
-     */
+    /** Convenience for setting the time in seconds from epoch. */
     template <class Integer>
     void
     set(Integer secondsFromEpoch)
@@ -61,9 +56,7 @@ public:
         set(time_point(duration(std::chrono::seconds(secondsFromEpoch))));
     }
 
-    /**
-     * Advance the clock by a duration.
-     */
+    /** Advance the clock by a duration. */
     template <class Rep, class Period>
     void
     advance(std::chrono::duration<Rep, Period> const& elapsed)
@@ -74,9 +67,7 @@ public:
         now_ += elapsed;
     }
 
-    /**
-     * Convenience for advancing the clock by one second.
-     */
+    /** Convenience for advancing the clock by one second. */
     ManualClock&
     operator++()
     {

include/xrpl/beast/container/aged_container_utility.h

@@ -4,16 +4,14 @@
 
 #include <chrono>
 #include <cstddef>
+#include <type_traits>
 
 namespace beast {
 
-/**
- * Expire aged container items past the specified age.
- */
+/** Expire aged container items past the specified age. */
 template <class AgedContainer, class Rep, class Period>
-std::size_t
+std::enable_if_t<IsAgedContainer<AgedContainer>::value, std::size_t>
 expire(AgedContainer& c, std::chrono::duration<Rep, Period> const& age)
-    requires(IsAgedContainer<AgedContainer>::value)
 {
     std::size_t n(0);
     auto const expired(c.clock().now() - age);

include/xrpl/beast/container/detail/aged_container_iterator.h

@@ -30,19 +30,20 @@ public:
 
     // Disable constructing a const_iterator from a non-const_iterator.
     // Converting between reverse and non-reverse iterators should be explicit.
-    template <bool OtherIsConst, class OtherIterator>
-    explicit AgedContainerIterator(AgedContainerIterator<OtherIsConst, OtherIterator> const& other)
-        requires(
+    template <
+        bool OtherIsConst,
+        class OtherIterator,
+        class = std::enable_if_t<
             (!OtherIsConst || IsConst) &&
-            !static_cast<bool>(std::is_same_v<Iterator, OtherIterator>))
+            !static_cast<bool>(std::is_same_v<Iterator, OtherIterator>)>>
+    explicit AgedContainerIterator(AgedContainerIterator<OtherIsConst, OtherIterator> const& other)
         : iter_(other.iter_)
     {
     }
 
     // Disable constructing a const_iterator from a non-const_iterator.
-    template <bool OtherIsConst>
+    template <bool OtherIsConst, class = std::enable_if_t<!OtherIsConst || IsConst>>
     AgedContainerIterator(AgedContainerIterator<OtherIsConst, Iterator> const& other)
-        requires(!OtherIsConst || IsConst)
         : iter_(other.iter_)
     {
     }
@@ -51,8 +52,7 @@ public:
     template <bool OtherIsConst, class OtherIterator>
     auto
     operator=(AgedContainerIterator<OtherIsConst, OtherIterator> const& other)
-        -> AgedContainerIterator&
-        requires(!OtherIsConst || IsConst)
+        -> std::enable_if_t<!OtherIsConst || IsConst, AgedContainerIterator&>
     {
         iter_ = other.iter_;
         return *this;

include/xrpl/beast/container/detail/aged_ordered_container.h

@@ -39,23 +39,22 @@ struct IsBoostReverseIterator<boost::intrusive::reverse_iterator<It>> : std::tru
     explicit IsBoostReverseIterator() = default;
 };
 
-/**
- * Associative container where each element is also indexed by time.
- *
- * This container mirrors the interface of the standard library ordered
- * associative containers, with the addition that each element is associated
- * with a `when` `time_point` which is obtained from the value of the clock's
- * `now`. The function `touch` updates the time for an element to the current
- * time as reported by the clock.
- *
- * An extra set of iterator types and member functions are provided in the
- * `chronological` memberspace that allow traversal in temporal or reverse
- * temporal order. This container is useful as a building block for caches
- * whose items expire after a certain amount of time. The chronological
- * iterators allow for fully customizable expiration strategies.
- *
- * @see aged_set, aged_multiset, aged_map, aged_multimap
- */
+/** Associative container where each element is also indexed by time.
+
+    This container mirrors the interface of the standard library ordered
+    associative containers, with the addition that each element is associated
+    with a `when` `time_point` which is obtained from the value of the clock's
+    `now`. The function `touch` updates the time for an element to the current
+    time as reported by the clock.
+
+    An extra set of iterator types and member functions are provided in the
+    `chronological` memberspace that allow traversal in temporal or reverse
+    temporal order. This container is useful as a building block for caches
+    whose items expire after a certain amount of time. The chronological
+    iterators allow for fully customizable expiration strategies.
+
+    @see aged_set, aged_multiset, aged_map, aged_multimap
+*/
 template <
     bool IsMulti,
     bool IsMap,
@@ -112,9 +111,10 @@ private:
         {
         }
 
-        template <class... Args>
+        template <
+            class... Args,
+            class = std::enable_if_t<std::is_constructible_v<value_type, Args...>>>
         Element(time_point const& when, Args&&... args)
-            requires(std::is_constructible_v<value_type, Args...>)
             : value(std::forward<Args>(args)...), when(when)
         {
         }
@@ -360,7 +360,6 @@ private:
     deleteElement(Element const* p)
     {
         ElementAllocatorTraits::destroy(config_.alloc(), p);
-        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
         ElementAllocatorTraits::deallocate(config_.alloc(), const_cast<Element*>(p), 1);
     }
 
@@ -609,25 +608,35 @@ public:
     //
     //--------------------------------------------------------------------------
 
-    template <class K, bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
+    template <
+        class K,
+        bool MaybeMulti = IsMulti,
+        bool MaybeMap = IsMap,
+        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
     std::conditional_t<IsMap, T, void*>&
-    at(K const& k)
-        requires(MaybeMap && !MaybeMulti);
+    at(K const& k);
 
-    template <class K, bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
+    template <
+        class K,
+        bool MaybeMulti = IsMulti,
+        bool MaybeMap = IsMap,
+        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
     std::conditional<IsMap, T, void*>::type const&
-    at(K const& k) const
-        requires(MaybeMap && !MaybeMulti);
+    at(K const& k) const;
 
-    template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
+    template <
+        bool MaybeMulti = IsMulti,
+        bool MaybeMap = IsMap,
+        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
     std::conditional_t<IsMap, T, void*>&
-    operator[](Key const& key)
-        requires(MaybeMap && !MaybeMulti);
+    operator[](Key const& key);
 
-    template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
+    template <
+        bool MaybeMulti = IsMulti,
+        bool MaybeMap = IsMap,
+        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
     std::conditional_t<IsMap, T, void*>&
-    operator[](Key&& key)
-        requires(MaybeMap && !MaybeMulti);
+    operator[](Key&& key);
 
     //--------------------------------------------------------------------------
     //
@@ -761,40 +770,35 @@ public:
     // map, set
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(value_type const& value) -> std::pair<iterator, bool>
-        requires(!MaybeMulti);
+    insert(value_type const& value) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(value_type const& value) -> iterator
-        requires MaybeMulti;
+    insert(value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>;
 
     // set
     template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     auto
-    insert(value_type&& value) -> std::pair<iterator, bool>
-        requires(!MaybeMulti && !MaybeMap);
+    insert(value_type&& value)
+        -> std::enable_if_t<!MaybeMulti && !MaybeMap, std::pair<iterator, bool>>;
 
     // multiset
     template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     auto
-    insert(value_type&& value) -> iterator
-        requires(MaybeMulti && !MaybeMap);
+    insert(value_type&& value) -> std::enable_if_t<MaybeMulti && !MaybeMap, iterator>;
 
     //---
 
     // map, set
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(const_iterator hint, value_type const& value) -> iterator
-        requires(!MaybeMulti);
+    insert(const_iterator hint, value_type const& value) -> std::enable_if_t<!MaybeMulti, iterator>;
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
-    iterator
+    std::enable_if_t<MaybeMulti, iterator>
     insert(const_iterator /*hint*/, value_type const& value)
-        requires MaybeMulti
     {
         // VFALCO TODO Figure out how to utilize 'hint'
         return insert(value);
@@ -803,14 +807,12 @@ public:
     // map, set
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(const_iterator hint, value_type&& value) -> iterator
-        requires(!MaybeMulti);
+    insert(const_iterator hint, value_type&& value) -> std::enable_if_t<!MaybeMulti, iterator>;
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
-    iterator
+    std::enable_if_t<MaybeMulti, iterator>
     insert(const_iterator /*hint*/, value_type&& value)
-        requires MaybeMulti
     {
         // VFALCO TODO Figure out how to utilize 'hint'
         return insert(std::move(value));
@@ -818,18 +820,20 @@ public:
 
     // map, multimap
     template <class P, bool MaybeMap = IsMap>
-    std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>
+    std::enable_if_t<
+        MaybeMap && std::is_constructible_v<value_type, P&&>,
+        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
     insert(P&& value)
-        requires(MaybeMap && std::is_constructible_v<value_type, P &&>)
     {
         return emplace(std::forward<P>(value));
     }
 
     // map, multimap
     template <class P, bool MaybeMap = IsMap>
-    std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>
+    std::enable_if_t<
+        MaybeMap && std::is_constructible_v<value_type, P&&>,
+        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
     insert(const_iterator hint, P&& value)
-        requires(MaybeMap && std::is_constructible_v<value_type, P &&>)
     {
         return emplaceHint(hint, std::forward<P>(value));
     }
@@ -851,45 +855,46 @@ public:
     // map, set
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> std::pair<iterator, bool>
-        requires(!MaybeMulti);
+    emplace(Args&&... args) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
 
     // multiset, multimap
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> iterator
-        requires MaybeMulti;
+    emplace(Args&&... args) -> std::enable_if_t<MaybeMulti, iterator>;
 
     // map, set
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplaceHint(const_iterator hint, Args&&... args) -> std::pair<iterator, bool>
-        requires(!MaybeMulti);
+    emplaceHint(const_iterator hint, Args&&... args)
+        -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
 
     // multiset, multimap
     template <bool MaybeMulti = IsMulti, class... Args>
-    iterator
+    std::enable_if_t<MaybeMulti, iterator>
     emplaceHint(const_iterator /*hint*/, Args&&... args)
-        requires MaybeMulti
     {
         // VFALCO TODO Figure out how to utilize 'hint'
         return emplace<MaybeMulti>(std::forward<Args>(args)...);
     }
 
-    // The constraint prevents erase (reverse_iterator pos) from compiling
-    template <bool IsConst, class Iterator>
+    // enable_if prevents erase (reverse_iterator pos) from compiling
+    template <
+        bool IsConst,
+        class Iterator,
+        class = std::enable_if_t<!IsBoostReverseIterator<Iterator>::value>>
     beast::detail::AgedContainerIterator<false, Iterator>
-    erase(beast::detail::AgedContainerIterator<IsConst, Iterator> pos)
-        requires(!IsBoostReverseIterator<Iterator>::value);
+    erase(beast::detail::AgedContainerIterator<IsConst, Iterator> pos);
 
-    // The constraint prevents erase (reverse_iterator first, reverse_iterator last)
+    // enable_if prevents erase (reverse_iterator first, reverse_iterator last)
     // from compiling
-    template <bool IsConst, class Iterator>
+    template <
+        bool IsConst,
+        class Iterator,
+        class = std::enable_if_t<!IsBoostReverseIterator<Iterator>::value>>
     beast::detail::AgedContainerIterator<false, Iterator>
     erase(
         beast::detail::AgedContainerIterator<IsConst, Iterator> first,
-        beast::detail::AgedContainerIterator<IsConst, Iterator> last)
-        requires(!IsBoostReverseIterator<Iterator>::value);
+        beast::detail::AgedContainerIterator<IsConst, Iterator> last);
 
     template <class K>
     auto
@@ -900,11 +905,13 @@ public:
 
     //--------------------------------------------------------------------------
 
-    // The constraint prevents touch (reverse_iterator pos) from compiling
-    template <bool IsConst, class Iterator>
+    // enable_if prevents touch (reverse_iterator pos) from compiling
+    template <
+        bool IsConst,
+        class Iterator,
+        class = std::enable_if_t<!IsBoostReverseIterator<Iterator>::value>>
     void
     touch(beast::detail::AgedContainerIterator<IsConst, Iterator> pos)
-        requires(!IsBoostReverseIterator<Iterator>::value)
     {
         touch(pos, clock().now());
     }
@@ -1135,25 +1142,25 @@ public:
     }
 
 private:
-    // The constraint prevents erase (reverse_iterator pos, now) from compiling
-    template <bool IsConst, class Iterator>
+    // enable_if prevents erase (reverse_iterator pos, now) from compiling
+    template <
+        bool IsConst,
+        class Iterator,
+        class = std::enable_if_t<!IsBoostReverseIterator<Iterator>::value>>
     void
     touch(
         beast::detail::AgedContainerIterator<IsConst, Iterator> pos,
-        clock_type::time_point const& now)
-        requires(!IsBoostReverseIterator<Iterator>::value);
+        clock_type::time_point const& now);
 
     template <
         bool MaybePropagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    void
-    swapData(AgedOrderedContainer& other) noexcept
-        requires MaybePropagate;
+    std::enable_if_t<MaybePropagate>
+    swapData(AgedOrderedContainer& other) noexcept;
 
     template <
         bool MaybePropagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    void
-    swapData(AgedOrderedContainer& other) noexcept
-        requires(!MaybePropagate);
+    std::enable_if_t<!MaybePropagate>
+    swapData(AgedOrderedContainer& other) noexcept;
 
 private:
     ConfigT config_;
@@ -1362,10 +1369,9 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operato
 //------------------------------------------------------------------------------
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <class K, bool MaybeMulti, bool MaybeMap>
+template <class K, bool MaybeMulti, bool MaybeMap, class>
 std::conditional_t<IsMap, T, void*>&
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::at(K const& k)
-    requires(MaybeMap && !MaybeMulti)
 {
     auto const iter(cont_.find(k, std::cref(config_.keyCompare())));
     if (iter == cont_.end())
@@ -1374,10 +1380,9 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::at(K co
 }
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <class K, bool MaybeMulti, bool MaybeMap>
+template <class K, bool MaybeMulti, bool MaybeMap, class>
 std::conditional<IsMap, T, void*>::type const&
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::at(K const& k) const
-    requires(MaybeMap && !MaybeMulti)
 {
     auto const iter(cont_.find(k, std::cref(config_.keyCompare())));
     if (iter == cont_.end())
@@ -1386,10 +1391,9 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::at(K co
 }
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <bool MaybeMulti, bool MaybeMap>
+template <bool MaybeMulti, bool MaybeMap, class>
 std::conditional_t<IsMap, T, void*>&
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operator[](Key const& key)
-    requires(MaybeMap && !MaybeMulti)
 {
     typename cont_type::insert_commit_data d;
     auto const result(cont_.insert_check(key, std::cref(config_.keyCompare()), d));
@@ -1405,10 +1409,9 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operato
 }
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <bool MaybeMulti, bool MaybeMap>
+template <bool MaybeMulti, bool MaybeMap, class>
 std::conditional_t<IsMap, T, void*>&
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operator[](Key&& key)
-    requires(MaybeMap && !MaybeMulti)
 {
     typename cont_type::insert_commit_data d;
     auto const result(cont_.insert_check(key, std::cref(config_.keyCompare()), d));
@@ -1442,8 +1445,7 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
-    value_type const& value) -> std::pair<iterator, bool>
-    requires(!MaybeMulti)
+    value_type const& value) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
 {
     typename cont_type::insert_commit_data d;
     auto const result(cont_.insert_check(extract(value), std::cref(config_.keyCompare()), d));
@@ -1462,8 +1464,7 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
-    value_type const& value) -> iterator
-    requires MaybeMulti
+    value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>
 {
     auto const before(cont_.upper_bound(extract(value), std::cref(config_.keyCompare())));
     Element* const p(newElement(value));
@@ -1477,8 +1478,7 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti, bool MaybeMap>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(value_type&& value)
-    -> std::pair<iterator, bool>
-    requires(!MaybeMulti && !MaybeMap)
+    -> std::enable_if_t<!MaybeMulti && !MaybeMap, std::pair<iterator, bool>>
 {
     typename cont_type::insert_commit_data d;
     auto const result(cont_.insert_check(extract(value), std::cref(config_.keyCompare()), d));
@@ -1497,8 +1497,7 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti, bool MaybeMap>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(value_type&& value)
-    -> iterator
-    requires(MaybeMulti && !MaybeMap)
+    -> std::enable_if_t<MaybeMulti && !MaybeMap, iterator>
 {
     auto const before(cont_.upper_bound(extract(value), std::cref(config_.keyCompare())));
     Element* const p(newElement(std::move(value)));
@@ -1515,8 +1514,7 @@ template <bool MaybeMulti>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
     const_iterator hint,
-    value_type const& value) -> iterator
-    requires(!MaybeMulti)
+    value_type const& value) -> std::enable_if_t<!MaybeMulti, iterator>
 {
     typename cont_type::insert_commit_data d;
     auto const result(
@@ -1537,8 +1535,7 @@ template <bool MaybeMulti>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
     const_iterator hint,
-    value_type&& value) -> iterator
-    requires(!MaybeMulti)
+    value_type&& value) -> std::enable_if_t<!MaybeMulti, iterator>
 {
     typename cont_type::insert_commit_data d;
     auto const result(
@@ -1558,8 +1555,7 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti, class... Args>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplace(Args&&... args)
-    -> std::pair<iterator, bool>
-    requires(!MaybeMulti)
+    -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
 {
     // VFALCO NOTE Its unfortunate that we need to
     //             construct element here
@@ -1581,8 +1577,7 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti, class... Args>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplace(Args&&... args)
-    -> iterator
-    requires MaybeMulti
+    -> std::enable_if_t<MaybeMulti, iterator>
 {
     Element* const p(newElement(std::forward<Args>(args)...));
     auto const before(cont_.upper_bound(extract(p->value), std::cref(config_.keyCompare())));
@@ -1597,8 +1592,7 @@ template <bool MaybeMulti, class... Args>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplaceHint(
     const_iterator hint,
-    Args&&... args) -> std::pair<iterator, bool>
-    requires(!MaybeMulti)
+    Args&&... args) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
 {
     // VFALCO NOTE Its unfortunate that we need to
     //             construct element here
@@ -1617,23 +1611,21 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplace
 }
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <bool IsConst, class Iterator>
+template <bool IsConst, class Iterator, class>
 beast::detail::AgedContainerIterator<false, Iterator>
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::erase(
     beast::detail::AgedContainerIterator<IsConst, Iterator> pos)
-    requires(!IsBoostReverseIterator<Iterator>::value)
 {
     unlinkAndDeleteElement(&*((pos++).iterator()));
     return beast::detail::AgedContainerIterator<false, Iterator>(pos.iterator());
 }
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <bool IsConst, class Iterator>
+template <bool IsConst, class Iterator, class>
 beast::detail::AgedContainerIterator<false, Iterator>
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::erase(
     beast::detail::AgedContainerIterator<IsConst, Iterator> first,
     beast::detail::AgedContainerIterator<IsConst, Iterator> last)
-    requires(!IsBoostReverseIterator<Iterator>::value)
 {
     for (; first != last;)
         unlinkAndDeleteElement(&*((first++).iterator()));
@@ -1736,12 +1728,11 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operato
 //------------------------------------------------------------------------------
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <bool IsConst, class Iterator>
+template <bool IsConst, class Iterator, class>
 void
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::touch(
     beast::detail::AgedContainerIterator<IsConst, Iterator> pos,
     clock_type::time_point const& now)
-    requires(!IsBoostReverseIterator<Iterator>::value)
 {
     auto& e(*pos.iterator());
     e.when = now;
@@ -1751,10 +1742,9 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::touch(
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
 template <bool MaybePropagate>
-void
+std::enable_if_t<MaybePropagate>
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::swapData(
     AgedOrderedContainer& other) noexcept
-    requires MaybePropagate
 {
     std::swap(config_.keyCompare(), other.config_.keyCompare());
     std::swap(config_.alloc(), other.config_.alloc());
@@ -1763,10 +1753,9 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::swapDat
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
 template <bool MaybePropagate>
-void
+std::enable_if_t<!MaybePropagate>
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::swapData(
     AgedOrderedContainer& other) noexcept
-    requires(!MaybePropagate)
 {
     std::swap(config_.keyCompare(), other.config_.keyCompare());
     std::swap(config_.clock, other.config_.clock);
@@ -1796,9 +1785,7 @@ swap(
     lhs.swap(rhs);
 }
 
-/**
- * Expire aged container items past the specified age.
- */
+/** Expire aged container items past the specified age. */
 template <
     bool IsMulti,
     bool IsMap,

include/xrpl/beast/container/detail/aged_unordered_container.h

@@ -43,24 +43,23 @@ TODO
 namespace beast {
 namespace detail {
 
-/**
- * Associative container where each element is also indexed by time.
- *
- * This container mirrors the interface of the standard library unordered
- * associative containers, with the addition that each element is associated
- * with a `when` `time_point` which is obtained from the value of the clock's
- * `now`. The function `touch` updates the time for an element to the current
- * time as reported by the clock.
- *
- * An extra set of iterator types and member functions are provided in the
- * `chronological` memberspace that allow traversal in temporal or reverse
- * temporal order. This container is useful as a building block for caches
- * whose items expire after a certain amount of time. The chronological
- * iterators allow for fully customizable expiration strategies.
- *
- * @see aged_unordered_set, aged_unordered_multiset
- * @see aged_unordered_map, aged_unordered_multimap
- */
+/** Associative container where each element is also indexed by time.
+
+    This container mirrors the interface of the standard library unordered
+    associative containers, with the addition that each element is associated
+    with a `when` `time_point` which is obtained from the value of the clock's
+    `now`. The function `touch` updates the time for an element to the current
+    time as reported by the clock.
+
+    An extra set of iterator types and member functions are provided in the
+    `chronological` memberspace that allow traversal in temporal or reverse
+    temporal order. This container is useful as a building block for caches
+    whose items expire after a certain amount of time. The chronological
+    iterators allow for fully customizable expiration strategies.
+
+    @see aged_unordered_set, aged_unordered_multiset
+    @see aged_unordered_map, aged_unordered_multimap
+*/
 template <
     bool IsMulti,
     bool IsMap,
@@ -118,9 +117,10 @@ private:
         {
         }
 
-        template <class... Args>
+        template <
+            class... Args,
+            class = std::enable_if_t<std::is_constructible_v<value_type, Args...>>>
         Element(time_point const& when, Args&&... args)
-            requires(std::is_constructible_v<value_type, Args...>)
             : value(std::forward<Args>(args)...), when(when)
         {
         }
@@ -529,7 +529,6 @@ private:
     deleteElement(Element const* p)
     {
         ElementAllocatorTraits::destroy(config_.alloc(), p);
-        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
         ElementAllocatorTraits::deallocate(config_.alloc(), const_cast<Element*>(p), 1);
     }
 
@@ -842,25 +841,35 @@ public:
     //
     //--------------------------------------------------------------------------
 
-    template <class K, bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
+    template <
+        class K,
+        bool MaybeMulti = IsMulti,
+        bool MaybeMap = IsMap,
+        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
     std::conditional_t<IsMap, T, void*>&
-    at(K const& k)
-        requires(MaybeMap && !MaybeMulti);
+    at(K const& k);
 
-    template <class K, bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
+    template <
+        class K,
+        bool MaybeMulti = IsMulti,
+        bool MaybeMap = IsMap,
+        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
     std::conditional<IsMap, T, void*>::type const&
-    at(K const& k) const
-        requires(MaybeMap && !MaybeMulti);
+    at(K const& k) const;
 
-    template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
+    template <
+        bool MaybeMulti = IsMulti,
+        bool MaybeMap = IsMap,
+        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
     std::conditional_t<IsMap, T, void*>&
-    operator[](Key const& key)
-        requires(MaybeMap && !MaybeMulti);
+    operator[](Key const& key);
 
-    template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
+    template <
+        bool MaybeMulti = IsMulti,
+        bool MaybeMap = IsMap,
+        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
     std::conditional_t<IsMap, T, void*>&
-    operator[](Key&& key)
-        requires(MaybeMap && !MaybeMulti);
+    operator[](Key&& key);
 
     //--------------------------------------------------------------------------
     //
@@ -958,32 +967,28 @@ public:
     // map, set
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(value_type const& value) -> std::pair<iterator, bool>
-        requires(!MaybeMulti);
+    insert(value_type const& value) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(value_type const& value) -> iterator
-        requires MaybeMulti;
+    insert(value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>;
 
     // map, set
     template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     auto
-    insert(value_type&& value) -> std::pair<iterator, bool>
-        requires(!MaybeMulti && !MaybeMap);
+    insert(value_type&& value)
+        -> std::enable_if_t<!MaybeMulti && !MaybeMap, std::pair<iterator, bool>>;
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     auto
-    insert(value_type&& value) -> iterator
-        requires(MaybeMulti && !MaybeMap);
+    insert(value_type&& value) -> std::enable_if_t<MaybeMulti && !MaybeMap, iterator>;
 
     // map, set
     template <bool MaybeMulti = IsMulti>
-    iterator
+    std::enable_if_t<!MaybeMulti, iterator>
     insert(const_iterator /*hint*/, value_type const& value)
-        requires(!MaybeMulti)
     {
         // Hint is ignored but we provide the interface so
         // callers may use ordered and unordered interchangeably.
@@ -992,9 +997,8 @@ public:
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
-    iterator
+    std::enable_if_t<MaybeMulti, iterator>
     insert(const_iterator /*hint*/, value_type const& value)
-        requires MaybeMulti
     {
         // VFALCO TODO The hint could be used to let
         //             the client order equal ranges
@@ -1003,9 +1007,8 @@ public:
 
     // map, set
     template <bool MaybeMulti = IsMulti>
-    iterator
+    std::enable_if_t<!MaybeMulti, iterator>
     insert(const_iterator /*hint*/, value_type&& value)
-        requires(!MaybeMulti)
     {
         // Hint is ignored but we provide the interface so
         // callers may use ordered and unordered interchangeably.
@@ -1014,9 +1017,8 @@ public:
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
-    iterator
+    std::enable_if_t<MaybeMulti, iterator>
     insert(const_iterator /*hint*/, value_type&& value)
-        requires MaybeMulti
     {
         // VFALCO TODO The hint could be used to let
         //             the client order equal ranges
@@ -1025,18 +1027,20 @@ public:
 
     // map, multimap
     template <class P, bool MaybeMap = IsMap>
-    std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>
+    std::enable_if_t<
+        MaybeMap && std::is_constructible_v<value_type, P&&>,
+        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
     insert(P&& value)
-        requires(MaybeMap && std::is_constructible_v<value_type, P &&>)
     {
         return emplace(std::forward<P>(value));
     }
 
     // map, multimap
     template <class P, bool MaybeMap = IsMap>
-    std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>
+    std::enable_if_t<
+        MaybeMap && std::is_constructible_v<value_type, P&&>,
+        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
     insert(const_iterator hint, P&& value)
-        requires(MaybeMap && std::is_constructible_v<value_type, P &&>)
     {
         return emplaceHint(hint, std::forward<P>(value));
     }
@@ -1057,26 +1061,23 @@ public:
     // set, map
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> std::pair<iterator, bool>
-        requires(!MaybeMulti);
+    emplace(Args&&... args) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
 
     // multiset, multimap
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> iterator
-        requires MaybeMulti;
+    emplace(Args&&... args) -> std::enable_if_t<MaybeMulti, iterator>;
 
     // set, map
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplaceHint(const_iterator /*hint*/, Args&&... args) -> std::pair<iterator, bool>
-        requires(!MaybeMulti);
+    emplaceHint(const_iterator /*hint*/, Args&&... args)
+        -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
 
     // multiset, multimap
     template <bool MaybeMulti = IsMulti, class... Args>
-    iterator
+    std::enable_if_t<MaybeMulti, iterator>
     emplaceHint(const_iterator /*hint*/, Args&&... args)
-        requires MaybeMulti
     {
         // VFALCO TODO The hint could be used for multi, to let
         //             the client order equal ranges
@@ -1307,7 +1308,7 @@ public:
         class OtherHash,
         class OtherAllocator,
         bool MaybeMulti = IsMulti>
-    bool
+    std::enable_if_t<!MaybeMulti, bool>
     operator==(AgedUnorderedContainer<
                false,
                OtherIsMap,
@@ -1316,8 +1317,7 @@ public:
                OtherDuration,
                OtherHash,
                KeyEqual,
-               OtherAllocator> const& other) const
-        requires(!MaybeMulti);
+               OtherAllocator> const& other) const;
 
     template <
         bool OtherIsMap,
@@ -1327,7 +1327,7 @@ public:
         class OtherHash,
         class OtherAllocator,
         bool MaybeMulti = IsMulti>
-    bool
+    std::enable_if_t<MaybeMulti, bool>
     operator==(AgedUnorderedContainer<
                true,
                OtherIsMap,
@@ -1336,8 +1336,7 @@ public:
                OtherDuration,
                OtherHash,
                KeyEqual,
-               OtherAllocator> const& other) const
-        requires MaybeMulti;
+               OtherAllocator> const& other) const;
 
     template <
         bool OtherIsMulti,
@@ -1382,14 +1381,13 @@ private:
     // map, set
     template <bool MaybeMulti = IsMulti>
     auto
-    insertUnchecked(value_type const& value) -> std::pair<iterator, bool>
-        requires(!MaybeMulti);
+    insertUnchecked(value_type const& value)
+        -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
     auto
-    insertUnchecked(value_type const& value) -> iterator
-        requires MaybeMulti;
+    insertUnchecked(value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>;
 
     template <class InputIt>
     void
@@ -1430,9 +1428,8 @@ private:
 
     template <
         bool MaybePropagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    void
+    std::enable_if_t<MaybePropagate>
     swapData(AgedUnorderedContainer& other) noexcept
-        requires MaybePropagate
     {
         std::swap(config_.hashFunction(), other.config_.hashFunction());
         std::swap(config_.keyEq(), other.config_.keyEq());
@@ -1442,9 +1439,8 @@ private:
 
     template <
         bool MaybePropagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    void
+    std::enable_if_t<!MaybePropagate>
     swapData(AgedUnorderedContainer& other) noexcept
-        requires(!MaybePropagate)
     {
         std::swap(config_.hashFunction(), other.config_.hashFunction());
         std::swap(config_.keyEq(), other.config_.keyEq());
@@ -2098,10 +2094,9 @@ template <
     class Hash,
     class KeyEqual,
     class Allocator>
-template <class K, bool MaybeMulti, bool MaybeMap>
+template <class K, bool MaybeMulti, bool MaybeMap, class>
 std::conditional_t<IsMap, T, void*>&
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::at(K const& k)
-    requires(MaybeMap && !MaybeMulti)
 {
     auto const iter(
         cont_.find(k, std::cref(config_.hashFunction()), std::cref(config_.keyValueEqual())));
@@ -2119,11 +2114,10 @@ template <
     class Hash,
     class KeyEqual,
     class Allocator>
-template <class K, bool MaybeMulti, bool MaybeMap>
+template <class K, bool MaybeMulti, bool MaybeMap, class>
 std::conditional<IsMap, T, void*>::type const&
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::at(
     K const& k) const
-    requires(MaybeMap && !MaybeMulti)
 {
     auto const iter(
         cont_.find(k, std::cref(config_.hashFunction()), std::cref(config_.keyValueEqual())));
@@ -2141,11 +2135,10 @@ template <
     class Hash,
     class KeyEqual,
     class Allocator>
-template <bool MaybeMulti, bool MaybeMap>
+template <bool MaybeMulti, bool MaybeMap, class>
 std::conditional_t<IsMap, T, void*>&
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator[](
     Key const& key)
-    requires(MaybeMap && !MaybeMulti)
 {
     maybeRehash(1);
     typename cont_type::insert_commit_data d;
@@ -2171,11 +2164,10 @@ template <
     class Hash,
     class KeyEqual,
     class Allocator>
-template <bool MaybeMulti, bool MaybeMap>
+template <bool MaybeMulti, bool MaybeMap, class>
 std::conditional_t<IsMap, T, void*>&
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator[](
     Key&& key)
-    requires(MaybeMap && !MaybeMulti)
 {
     maybeRehash(1);
     typename cont_type::insert_commit_data d;
@@ -2228,8 +2220,7 @@ template <
 template <bool MaybeMulti>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type const& value) -> std::pair<iterator, bool>
-    requires(!MaybeMulti)
+    value_type const& value) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
 {
     maybeRehash(1);
     typename cont_type::insert_commit_data d;
@@ -2258,8 +2249,7 @@ template <
 template <bool MaybeMulti>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type const& value) -> iterator
-    requires MaybeMulti
+    value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>
 {
     maybeRehash(1);
     Element* const p(newElement(value));
@@ -2281,8 +2271,7 @@ template <
 template <bool MaybeMulti, bool MaybeMap>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type&& value) -> std::pair<iterator, bool>
-    requires(!MaybeMulti && !MaybeMap)
+    value_type&& value) -> std::enable_if_t<!MaybeMulti && !MaybeMap, std::pair<iterator, bool>>
 {
     maybeRehash(1);
     typename cont_type::insert_commit_data d;
@@ -2311,8 +2300,7 @@ template <
 template <bool MaybeMulti, bool MaybeMap>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type&& value) -> iterator
-    requires(MaybeMulti && !MaybeMap)
+    value_type&& value) -> std::enable_if_t<MaybeMulti && !MaybeMap, iterator>
 {
     maybeRehash(1);
     Element* const p(newElement(std::move(value)));
@@ -2321,6 +2309,7 @@ AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>
     return iterator(iter);
 }
 
+#if 1  // Use insert() instead of insert_check() insert_commit()
 // set, map
 template <
     bool IsMulti,
@@ -2334,8 +2323,7 @@ template <
 template <bool MaybeMulti, class... Args>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplace(
-    Args&&... args) -> std::pair<iterator, bool>
-    requires(!MaybeMulti)
+    Args&&... args) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
 {
     maybeRehash(1);
     // VFALCO NOTE Its unfortunate that we need to
@@ -2350,6 +2338,42 @@ AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>
     deleteElement(p);
     return std::make_pair(iterator(result.first), false);
 }
+#else   // As original, use insert_check() / insert_commit () pair.
+// set, map
+template <
+    bool IsMulti,
+    bool IsMap,
+    class Key,
+    class T,
+    class Clock,
+    class Hash,
+    class KeyEqual,
+    class Allocator>
+template <bool maybe_multi, class... Args>
+auto
+AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplace(
+    Args&&... args) -> typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type
+{
+    maybe_rehash(1);
+    // VFALCO NOTE Its unfortunate that we need to
+    //             construct element here
+    element* const p(new_element(std::forward<Args>(args)...));
+    typename cont_type::insert_commit_data d;
+    auto const result(m_cont.insert_check(
+        extract(p->value),
+        std::cref(m_config.hashFunction()),
+        std::cref(m_config.keyValueEqual()),
+        d));
+    if (result.second)
+    {
+        auto const iter(m_cont.insert_commit(*p, d));
+        chronological.list.push_back(*p);
+        return std::make_pair(iterator(iter), true);
+    }
+    delete_element(p);
+    return std::make_pair(iterator(result.first), false);
+}
+#endif  // 0
 
 // multiset, multimap
 template <
@@ -2364,8 +2388,7 @@ template <
 template <bool MaybeMulti, class... Args>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplace(
-    Args&&... args) -> iterator
-    requires MaybeMulti
+    Args&&... args) -> std::enable_if_t<MaybeMulti, iterator>
 {
     maybeRehash(1);
     Element* const p(newElement(std::forward<Args>(args)...));
@@ -2388,8 +2411,7 @@ template <bool MaybeMulti, class... Args>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplaceHint(
     const_iterator /*hint*/,
-    Args&&... args) -> std::pair<iterator, bool>
-    requires(!MaybeMulti)
+    Args&&... args) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
 {
     maybeRehash(1);
     // VFALCO NOTE Its unfortunate that we need to
@@ -2540,7 +2562,7 @@ template <
     class OtherHash,
     class OtherAllocator,
     bool MaybeMulti>
-bool
+std::enable_if_t<!MaybeMulti, bool>
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator==(
     AgedUnorderedContainer<
         false,
@@ -2551,7 +2573,6 @@ AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>
         OtherHash,
         KeyEqual,
         OtherAllocator> const& other) const
-    requires(!MaybeMulti)
 {
     if (size() != other.size())
         return false;
@@ -2581,7 +2602,7 @@ template <
     class OtherHash,
     class OtherAllocator,
     bool MaybeMulti>
-bool
+std::enable_if_t<MaybeMulti, bool>
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator==(
     AgedUnorderedContainer<
         true,
@@ -2592,7 +2613,6 @@ AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>
         OtherHash,
         KeyEqual,
         OtherAllocator> const& other) const
-    requires MaybeMulti
 {
     if (size() != other.size())
         return false;
@@ -2629,8 +2649,7 @@ template <
 template <bool MaybeMulti>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insertUnchecked(
-    value_type const& value) -> std::pair<iterator, bool>
-    requires(!MaybeMulti)
+    value_type const& value) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
 {
     typename cont_type::insert_commit_data d;
     auto const result(cont_.insert_check(
@@ -2658,8 +2677,7 @@ template <
 template <bool MaybeMulti>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insertUnchecked(
-    value_type const& value) -> iterator
-    requires MaybeMulti
+    value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>
 {
     Element* const p(newElement(value));
     chronological.list_.push_back(*p);
@@ -2710,9 +2728,7 @@ swap(
     lhs.swap(rhs);
 }
 
-/**
- * Expire aged container items past the specified age.
- */
+/** Expire aged container items past the specified age. */
 template <
     bool IsMulti,
     bool IsMap,

include/xrpl/beast/core/CurrentThreadName.h

@@ -12,10 +12,9 @@
 
 namespace beast {
 
-/**
- * Changes the name of the caller thread.
- * Different OSes may place different length or content limits on this name.
- */
+/** Changes the name of the caller thread.
+    Different OSes may place different length or content limits on this name.
+*/
 void
 setCurrentThreadName(std::string_view newThreadName);
 
@@ -25,14 +24,13 @@ setCurrentThreadName(std::string_view newThreadName);
 // Maximum number of characters is therefore 15.
 constexpr std::size_t kMaxThreadNameLength = 15;
 
-/**
- * Sets the name of the caller thread with compile-time size checking.
- * @tparam N The size of the string literal including null terminator
- * @param newThreadName A string literal to set as the thread name
- *
- * This template overload enforces that thread names are at most 16 characters
- * (including null terminator) at compile time, matching Linux's limit.
- */
+/** Sets the name of the caller thread with compile-time size checking.
+    @tparam N The size of the string literal including null terminator
+    @param newThreadName A string literal to set as the thread name
+
+    This template overload enforces that thread names are at most 16 characters
+    (including null terminator) at compile time, matching Linux's limit.
+*/
 template <std::size_t N>
 void
 setCurrentThreadName(char const (&newThreadName)[N])
@@ -43,15 +41,14 @@ setCurrentThreadName(char const (&newThreadName)[N])
 }
 #endif
 
-/**
- * Returns the name of the caller thread.
- *
- * The name returned is the name as set by a call to setCurrentThreadName().
- * If the thread name is set by an external force, then that name change
- * will not be reported.
- *
- * If no name has ever been set, then the empty string is returned.
- */
+/** Returns the name of the caller thread.
+
+    The name returned is the name as set by a call to setCurrentThreadName().
+    If the thread name is set by an external force, then that name change
+    will not be reported.
+
+    If no name has ever been set, then the empty string is returned.
+*/
 std::string
 getCurrentThreadName();
 

include/xrpl/beast/core/LexicalCast.h

@@ -29,18 +29,16 @@ struct LexicalCast<std::string, In>
     explicit LexicalCast() = default;
 
     template <class Arithmetic = In>
-    bool
+    std::enable_if_t<std::is_arithmetic_v<Arithmetic>, bool>
     operator()(std::string& out, Arithmetic in)
-        requires(std::is_arithmetic_v<Arithmetic>)
     {
         out = std::to_string(in);
         return true;
     }
 
     template <class Enumeration = In>
-    bool
+    std::enable_if_t<std::is_enum_v<Enumeration>, bool>
     operator()(std::string& out, Enumeration in)
-        requires(std::is_enum_v<Enumeration>)
     {
         out = std::to_string(static_cast<std::underlying_type_t<Enumeration>>(in));
         return true;
@@ -58,9 +56,8 @@ struct LexicalCast<Out, std::string_view>
         "beast::LexicalCast can only be used with integral types");
 
     template <class Integral = Out>
-    bool
+    std::enable_if_t<std::is_integral_v<Integral> && !std::is_same_v<Integral, bool>, bool>
     operator()(Integral& out, std::string_view in) const
-        requires(std::is_integral_v<Integral> && !std::is_same_v<Integral, bool>)
     {
         auto first = in.data();
         auto last = in.data() + in.size();
@@ -163,19 +160,17 @@ struct LexicalCast<Out, char*>
 
 //------------------------------------------------------------------------------
 
-/**
- * Thrown when a conversion is not possible with LexicalCast.
- * Only used in the throw variants of lexicalCast.
- */
+/** Thrown when a conversion is not possible with LexicalCast.
+    Only used in the throw variants of lexicalCast.
+*/
 struct BadLexicalCast : public std::bad_cast
 {
     explicit BadLexicalCast() = default;
 };
 
-/**
- * Intelligently convert from one type to another.
- * @return `false` if there was a parsing or range error
- */
+/** Intelligently convert from one type to another.
+    @return `false` if there was a parsing or range error
+*/
 template <class Out, class In>
 bool
 lexicalCastChecked(Out& out, In in)
@@ -183,13 +178,12 @@ lexicalCastChecked(Out& out, In in)
     return detail::LexicalCast<Out, In>()(out, in);
 }
 
-/**
- * Convert from one type to another, throw on error
- *
- * An exception of type BadLexicalCast is thrown if the conversion fails.
- *
- * @return The new type.
- */
+/** Convert from one type to another, throw on error
+
+    An exception of type BadLexicalCast is thrown if the conversion fails.
+
+    @return The new type.
+*/
 template <class Out, class In>
 Out
 lexicalCastThrow(In in)
@@ -200,12 +194,11 @@ lexicalCastThrow(In in)
     throw BadLexicalCast();
 }
 
-/**
- * Convert from one type to another.
- *
- * @param defaultValue The value returned if parsing fails
- * @return The new type.
- */
+/** Convert from one type to another.
+
+    @param defaultValue The value returned if parsing fails
+    @return The new type.
+*/
 template <class Out, class In>
 Out
 lexicalCast(In in, Out defaultValue = Out())

include/xrpl/beast/core/List.h

@@ -11,9 +11,7 @@ class List;
 
 namespace detail {
 
-/**
- * Copy `const` attribute from T to U if present.
- */
+/** Copy `const` attribute from T to U if present. */
 /** @{ */
 template <typename T, typename U>
 struct CopyConst
@@ -155,111 +153,110 @@ private:
 
 }  // namespace detail
 
-/**
- * Intrusive doubly linked list.
- *
- * This intrusive List is a container similar in operation to std::list in the
- * Standard Template Library (STL). Like all @ref intrusive containers, List
- * requires you to first derive your class from List<>::Node:
- *
- * @code
- *
- * struct Object : List <Object>::Node
- * {
- *     explicit Object (int value) : value_ (value)
- *     {
- *     }
- *
- *     int value_;
- * };
- *
- * @endcode
- *
- * Now we define the list, and add a couple of items.
- *
- * @code
- *
- * List <Object> list;
- *
- * list.push_back (* (new Object (1)));
- * list.push_back (* (new Object (2)));
- *
- * @endcode
- *
- * For compatibility with the standard containers, push_back() expects a
- * reference to the object. Unlike the standard container, however, push_back()
- * places the actual object in the list and not a copy-constructed duplicate.
- *
- * Iterating over the list follows the same idiom as the STL:
- *
- * @code
- *
- * for (List <Object>::iterator iter = list.begin(); iter != list.end; ++iter)
- *     std::cout << iter->value_;
- *
- * @endcode
- *
- * You can even use BOOST_FOREACH, or range based for loops:
- *
- * @code
- *
- * BOOST_FOREACH (Object& object, list)  // boost only
- *     std::cout << object.value_;
- *
- * for (Object& object : list)           // C++11 only
- *     std::cout << object.value_;
- *
- * @endcode
- *
- * Because List is mostly STL compliant, it can be passed into STL algorithms:
- * e.g. `std::for_each()` or `std::find_first_of()`.
- *
- * In general, objects placed into a List should be dynamically allocated
- * although this cannot be enforced at compile time. Since the caller provides
- * the storage for the object, the caller is also responsible for deleting the
- * object. An object still exists after being removed from a List, until the
- * caller deletes it. This means an element can be moved from one List to
- * another with practically no overhead.
- *
- * Unlike the standard containers, an object may only exist in one list at a
- * time, unless special preparations are made. The Tag template parameter is
- * used to distinguish between different list types for the same object,
- * allowing the object to exist in more than one list simultaneously.
- *
- * For example, consider an actor system where a global list of actors is
- * maintained, so that they can each be periodically receive processing
- * time. We wish to also maintain a list of the subset of actors that require
- * a domain-dependent update. To achieve this, we declare two tags, the
- * associated list types, and the list element thusly:
- *
- * @code
- *
- * struct Actor;         // Forward declaration required
- *
- * struct ProcessTag { };
- * struct UpdateTag { };
- *
- * using ProcessList = List <Actor, ProcessTag>;
- * using UpdateList = List <Actor, UpdateTag>;
- *
- * // Derive from both node types so we can be in each list at once.
- * //
- * struct Actor : ProcessList::Node, UpdateList::Node
- * {
- *     bool process ();    // returns true if we need an update
- *     void update ();
- * };
- *
- * @endcode
- *
- * @tparam T The base type of element which the list will store
- *                 pointers to.
- *
- * @tparam Tag An optional unique type name used to distinguish lists and
- * nodes, when the object can exist in multiple lists simultaneously.
- *
- * @ingroup beast_core intrusive
- */
+/** Intrusive doubly linked list.
+
+    This intrusive List is a container similar in operation to std::list in the
+    Standard Template Library (STL). Like all @ref intrusive containers, List
+    requires you to first derive your class from List<>::Node:
+
+    @code
+
+    struct Object : List <Object>::Node
+    {
+        explicit Object (int value) : value_ (value)
+        {
+        }
+
+        int value_;
+    };
+
+    @endcode
+
+    Now we define the list, and add a couple of items.
+
+    @code
+
+    List <Object> list;
+
+    list.push_back (* (new Object (1)));
+    list.push_back (* (new Object (2)));
+
+    @endcode
+
+    For compatibility with the standard containers, push_back() expects a
+    reference to the object. Unlike the standard container, however, push_back()
+    places the actual object in the list and not a copy-constructed duplicate.
+
+    Iterating over the list follows the same idiom as the STL:
+
+    @code
+
+    for (List <Object>::iterator iter = list.begin(); iter != list.end; ++iter)
+        std::cout << iter->value_;
+
+    @endcode
+
+    You can even use BOOST_FOREACH, or range based for loops:
+
+    @code
+
+    BOOST_FOREACH (Object& object, list)  // boost only
+        std::cout << object.value_;
+
+    for (Object& object : list)           // C++11 only
+        std::cout << object.value_;
+
+    @endcode
+
+    Because List is mostly STL compliant, it can be passed into STL algorithms:
+    e.g. `std::for_each()` or `std::find_first_of()`.
+
+    In general, objects placed into a List should be dynamically allocated
+    although this cannot be enforced at compile time. Since the caller provides
+    the storage for the object, the caller is also responsible for deleting the
+    object. An object still exists after being removed from a List, until the
+    caller deletes it. This means an element can be moved from one List to
+    another with practically no overhead.
+
+    Unlike the standard containers, an object may only exist in one list at a
+    time, unless special preparations are made. The Tag template parameter is
+    used to distinguish between different list types for the same object,
+    allowing the object to exist in more than one list simultaneously.
+
+    For example, consider an actor system where a global list of actors is
+    maintained, so that they can each be periodically receive processing
+    time. We wish to also maintain a list of the subset of actors that require
+    a domain-dependent update. To achieve this, we declare two tags, the
+    associated list types, and the list element thusly:
+
+    @code
+
+    struct Actor;         // Forward declaration required
+
+    struct ProcessTag { };
+    struct UpdateTag { };
+
+    using ProcessList = List <Actor, ProcessTag>;
+    using UpdateList = List <Actor, UpdateTag>;
+
+    // Derive from both node types so we can be in each list at once.
+    //
+    struct Actor : ProcessList::Node, UpdateList::Node
+    {
+        bool process ();    // returns true if we need an update
+        void update ();
+    };
+
+    @endcode
+
+    @tparam T The base type of element which the list will store
+                    pointers to.
+
+    @tparam Tag An optional unique type name used to distinguish lists and
+   nodes, when the object can exist in multiple lists simultaneously.
+
+    @ingroup beast_core intrusive
+*/
 template <typename T, typename Tag = void>
 class List
 {
@@ -277,9 +274,7 @@ public:
     using iterator = detail::ListIterator<Node>;
     using const_iterator = detail::ListIterator<Node const>;
 
-    /**
-     * Create an empty list.
-     */
+    /** Create an empty list. */
     List()
     {
         head_.prev_ = nullptr;  // identifies the head
@@ -291,133 +286,119 @@ public:
     List&
     operator=(List const&) = delete;
 
-    /**
-     * Determine if the list is empty.
-     * @return `true` if the list is empty.
-     */
+    /** Determine if the list is empty.
+        @return `true` if the list is empty.
+    */
     [[nodiscard]] bool
     empty() const noexcept
     {
         return size() == 0;
     }
 
-    /**
-     * Returns the number of elements in the list.
-     */
+    /** Returns the number of elements in the list. */
     [[nodiscard]] size_type
     size() const noexcept
     {
         return size_;
     }
 
-    /**
-     * Obtain a reference to the first element.
-     * @invariant The list may not be empty.
-     * @return A reference to the first element.
-     */
+    /** Obtain a reference to the first element.
+        @invariant The list may not be empty.
+        @return A reference to the first element.
+    */
     reference
     front() noexcept
     {
         return element_from(head_.next_);
     }
 
-    /**
-     * Obtain a const reference to the first element.
-     * @invariant The list may not be empty.
-     * @return A const reference to the first element.
-     */
+    /** Obtain a const reference to the first element.
+        @invariant The list may not be empty.
+        @return A const reference to the first element.
+    */
     [[nodiscard]] const_reference
     front() const noexcept
     {
         return element_from(head_.next_);
     }
 
-    /**
-     * Obtain a reference to the last element.
-     * @invariant The list may not be empty.
-     * @return A reference to the last element.
-     */
+    /** Obtain a reference to the last element.
+        @invariant The list may not be empty.
+        @return A reference to the last element.
+    */
     reference
     back() noexcept
     {
         return element_from(tail_.prev_);
     }
 
-    /**
-     * Obtain a const reference to the last element.
-     * @invariant The list may not be empty.
-     * @return A const reference to the last element.
-     */
+    /** Obtain a const reference to the last element.
+        @invariant The list may not be empty.
+        @return A const reference to the last element.
+    */
     [[nodiscard]] const_reference
     back() const noexcept
     {
         return element_from(tail_.prev_);
     }
 
-    /**
-     * Obtain an iterator to the beginning of the list.
-     * @return An iterator pointing to the beginning of the list.
-     */
+    /** Obtain an iterator to the beginning of the list.
+        @return An iterator pointing to the beginning of the list.
+    */
     iterator
     begin() noexcept
     {
         return iterator(head_.next_);
     }
 
-    /**
-     * Obtain a const iterator to the beginning of the list.
-     * @return A const iterator pointing to the beginning of the list.
-     */
+    /** Obtain a const iterator to the beginning of the list.
+        @return A const iterator pointing to the beginning of the list.
+    */
     [[nodiscard]] const_iterator
     begin() const noexcept
     {
         return const_iterator(head_.next_);
     }
 
-    /**
-     * Obtain a const iterator to the beginning of the list.
-     * @return A const iterator pointing to the beginning of the list.
-     */
+    /** Obtain a const iterator to the beginning of the list.
+        @return A const iterator pointing to the beginning of the list.
+    */
     [[nodiscard]] const_iterator
     cbegin() const noexcept
     {
         return const_iterator(head_.next_);
     }
 
-    /**
-     * Obtain a iterator to the end of the list.
-     * @return An iterator pointing to the end of the list.
-     */
+    /** Obtain a iterator to the end of the list.
+        @return An iterator pointing to the end of the list.
+    */
     iterator
     end() noexcept
     {
         return iterator(&tail_);
     }
 
-    /**
-     * Obtain a const iterator to the end of the list.
-     * @return A constiterator pointing to the end of the list.
-     */
+    /** Obtain a const iterator to the end of the list.
+        @return A constiterator pointing to the end of the list.
+    */
     [[nodiscard]] const_iterator
     end() const noexcept
     {
         return const_iterator(&tail_);
     }
 
-    /**
-     * Obtain a const iterator to the end of the list
-     * @return A constiterator pointing to the end of the list.
-     */
+    /** Obtain a const iterator to the end of the list
+        @return A constiterator pointing to the end of the list.
+    */
     [[nodiscard]] const_iterator
     cend() const noexcept
     {
         return const_iterator(&tail_);
     }
 
-    /**
-     * Clear the list.
-     * @note This does not free the elements.
-     */
+    /** Clear the list.
+        @note This does not free the elements.
+    */
     void
     clear() noexcept
     {
@@ -426,13 +407,12 @@ public:
         size_ = 0;
     }
 
-    /**
-     * Insert an element.
-     * @invariant The element must not already be in the list.
-     * @param pos The location to insert after.
-     * @param element The element to insert.
-     * @return An iterator pointing to the newly inserted element.
-     */
+    /** Insert an element.
+        @invariant The element must not already be in the list.
+        @param pos The location to insert after.
+        @param element The element to insert.
+        @return An iterator pointing to the newly inserted element.
+    */
     iterator
     insert(iterator pos, T& element) noexcept
     {
@@ -445,12 +425,11 @@ public:
         return iterator(node);
     }
 
-    /**
-     * Insert another list into this one.
-     * The other list is cleared.
-     * @param pos The location to insert after.
-     * @param other The list to insert.
-     */
+    /** Insert another list into this one.
+        The other list is cleared.
+        @param pos The location to insert after.
+        @param other The list to insert.
+    */
     void
     insert(iterator pos, List& other) noexcept
     {
@@ -466,12 +445,11 @@ public:
         }
     }
 
-    /**
-     * Remove an element.
-     * @invariant The element must exist in the list.
-     * @param pos An iterator pointing to the element to remove.
-     * @return An iterator pointing to the next element after the one removed.
-     */
+    /** Remove an element.
+        @invariant The element must exist in the list.
+        @param pos An iterator pointing to the element to remove.
+        @return An iterator pointing to the next element after the one removed.
+    */
     iterator
     erase(iterator pos) noexcept
     {
@@ -483,22 +461,20 @@ public:
         return pos;
     }
 
-    /**
-     * Insert an element at the beginning of the list.
-     * @invariant The element must not exist in the list.
-     * @param element The element to insert.
-     */
+    /** Insert an element at the beginning of the list.
+        @invariant The element must not exist in the list.
+        @param element The element to insert.
+    */
     iterator
     pushFront(T& element) noexcept
     {
         return insert(begin(), element);
     }
 
-    /**
-     * Remove the element at the beginning of the list.
-     * @invariant The list must not be empty.
-     * @return A reference to the popped element.
-     */
+    /** Remove the element at the beginning of the list.
+        @invariant The list must not be empty.
+        @return A reference to the popped element.
+    */
     T&
     popFront() noexcept
     {
@@ -507,22 +483,20 @@ public:
         return element;
     }
 
-    /**
-     * Append an element at the end of the list.
-     * @invariant The element must not exist in the list.
-     * @param element The element to append.
-     */
+    /** Append an element at the end of the list.
+        @invariant The element must not exist in the list.
+        @param element The element to append.
+    */
     iterator
     pushBack(T& element) noexcept
     {
         return insert(end(), element);
     }
 
-    /**
-     * Remove the element at the end of the list.
-     * @invariant The list must not be empty.
-     * @return A reference to the popped element.
-     */
+    /** Remove the element at the end of the list.
+        @invariant The list must not be empty.
+        @return A reference to the popped element.
+    */
     T&
     popBack() noexcept
     {
@@ -531,9 +505,7 @@ public:
         return element;
     }
 
-    /**
-     * Swap contents with another list.
-     */
+    /** Swap contents with another list. */
     void
     swap(List& other) noexcept
     {
@@ -543,46 +515,42 @@ public:
         append(temp);
     }
 
-    /**
-     * Insert another list at the beginning of this list.
-     * The other list is cleared.
-     * @param list The other list to insert.
-     */
+    /** Insert another list at the beginning of this list.
+        The other list is cleared.
+        @param list The other list to insert.
+    */
     iterator
     prepend(List& list) noexcept
     {
         return insert(begin(), list);
     }
 
-    /**
-     * Append another list at the end of this list.
-     * The other list is cleared.
-     * @param list the other list to append.
-     */
+    /** Append another list at the end of this list.
+        The other list is cleared.
+        @param list the other list to append.
+    */
     iterator
     append(List& list) noexcept
     {
         return insert(end(), list);
     }
 
-    /**
-     * Obtain an iterator from an element.
-     * @invariant The element must exist in the list.
-     * @param element The element to obtain an iterator for.
-     * @return An iterator to the element.
-     */
+    /** Obtain an iterator from an element.
+        @invariant The element must exist in the list.
+        @param element The element to obtain an iterator for.
+        @return An iterator to the element.
+    */
     iterator
     iteratorTo(T& element) const noexcept
     {
         return iterator(static_cast<Node*>(&element));
     }
 
-    /**
-     * Obtain a const iterator from an element.
-     * @invariant The element must exist in the list.
-     * @param element The element to obtain an iterator for.
-     * @return A const iterator to the element.
-     */
+    /** Obtain a const iterator from an element.
+        @invariant The element must exist in the list.
+        @param element The element to obtain an iterator for.
+        @return A const iterator to the element.
+    */
     [[nodiscard]] const_iterator
     constIteratorTo(T const& element) const noexcept
     {

include/xrpl/beast/core/LockFreeStack.h

@@ -41,7 +41,7 @@ public:
     operator=(NodePtr node)
     {
         node_ = node;
-        return *this;
+        return static_cast<LockFreeStackIterator&>(*this);
     }
 
     LockFreeStackIterator&
@@ -103,19 +103,18 @@ operator!=(
 
 //------------------------------------------------------------------------------
 
-/**
- * Multiple Producer, Multiple Consumer (MPMC) intrusive stack.
- *
- * This stack is implemented using the same intrusive interface as List.
- * All mutations are lock-free.
- *
- * The caller is responsible for preventing the "ABA" problem:
- *     http://en.wikipedia.org/wiki/ABA_problem
- *
- * @param Tag  A type name used to distinguish lists and nodes, for
- *             putting objects in multiple lists. If this parameter is
- *             omitted, the default tag is used.
- */
+/** Multiple Producer, Multiple Consumer (MPMC) intrusive stack.
+
+    This stack is implemented using the same intrusive interface as List.
+    All mutations are lock-free.
+
+    The caller is responsible for preventing the "ABA" problem:
+        http://en.wikipedia.org/wiki/ABA_problem
+
+    @param Tag  A type name used to distinguish lists and nodes, for
+                putting objects in multiple lists. If this parameter is
+                omitted, the default tag is used.
+*/
 template <class Element, class Tag = void>
 class LockFreeStack
 {
@@ -163,27 +162,24 @@ public:
     LockFreeStack&
     operator=(LockFreeStack const&) = delete;
 
-    /**
-     * Returns true if the stack is empty.
-     */
+    /** Returns true if the stack is empty. */
     [[nodiscard]] bool
     empty() const
     {
         return head_.load() == &end_;
     }
 
-    /**
-     * Push a node onto the stack.
-     * The caller is responsible for preventing the ABA problem.
-     * This operation is lock-free.
-     * Thread safety:
-     *     Safe to call from any thread.
-     *
-     * @param node The node to push.
-     *
-     * @return `true` if the stack was previously empty. If multiple threads
-     *         are attempting to push, only one will receive `true`.
-     */
+    /** Push a node onto the stack.
+        The caller is responsible for preventing the ABA problem.
+        This operation is lock-free.
+        Thread safety:
+            Safe to call from any thread.
+
+        @param node The node to push.
+
+        @return `true` if the stack was previously empty. If multiple threads
+                are attempting to push, only one will receive `true`.
+    */
     // VFALCO NOTE Fix this, shouldn't it be a reference like intrusive list?
     bool
     pushFront(Node* node)
@@ -199,16 +195,15 @@ public:
         return first;
     }
 
-    /**
-     * Pop an element off the stack.
-     * The caller is responsible for preventing the ABA problem.
-     * This operation is lock-free.
-     * Thread safety:
-     *     Safe to call from any thread.
-     *
-     * @return The element that was popped, or `nullptr` if the stack
-     *         was empty.
-     */
+    /** Pop an element off the stack.
+        The caller is responsible for preventing the ABA problem.
+        This operation is lock-free.
+        Thread safety:
+            Safe to call from any thread.
+
+        @return The element that was popped, or `nullptr` if the stack
+                was empty.
+    */
     Element*
     popFront()
     {
@@ -224,13 +219,12 @@ public:
         return static_cast<Element*>(node);
     }
 
-    /**
-     * Return a forward iterator to the beginning or end of the stack.
-     * Undefined behavior results if push_front or pop_front is called
-     * while an iteration is in progress.
-     * Thread safety:
-     *     Caller is responsible for synchronization.
-     */
+    /** Return a forward iterator to the beginning or end of the stack.
+        Undefined behavior results if push_front or pop_front is called
+        while an iteration is in progress.
+        Thread safety:
+            Caller is responsible for synchronization.
+    */
     /** @{ */
     iterator
     begin()

include/xrpl/beast/core/SemanticVersion.h

@@ -6,14 +6,13 @@
 
 namespace beast {
 
-/**
- * A Semantic Version number.
- *
- * Identifies the build of a particular version of software using
- * the Semantic Versioning Specification described here:
- *
- * http://semver.org/
- */
+/** A Semantic Version number.
+
+    Identifies the build of a particular version of software using
+    the Semantic Versioning Specification described here:
+
+    http://semver.org/
+*/
 class SemanticVersion
 {
 public:
@@ -30,17 +29,14 @@ public:
 
     SemanticVersion(std::string_view version);
 
-    /**
-     * Parse a semantic version string.
-     * The parsing is as strict as possible.
-     * @return `true` if the string was parsed.
-     */
+    /** Parse a semantic version string.
+        The parsing is as strict as possible.
+        @return `true` if the string was parsed.
+    */
     bool
     parse(std::string_view input);
 
-    /**
-     * Produce a string from semantic version components.
-     */
+    /** Produce a string from semantic version components. */
     [[nodiscard]] std::string
     print() const;
 
@@ -56,10 +52,9 @@ public:
     }
 };
 
-/**
- * Compare two SemanticVersions against each other.
- * The comparison follows the rules as per the specification.
- */
+/** Compare two SemanticVersions against each other.
+    The comparison follows the rules as per the specification.
+*/
 int
 compare(SemanticVersion const& lhs, SemanticVersion const& rhs);
 

include/xrpl/beast/hash/hash_append.h

@@ -26,7 +26,7 @@ template <class T>
 inline void
 reverseBytes(T& t)
 {
-    auto* bytes =
+    unsigned char* bytes =
         static_cast<unsigned char*>(std::memmove(std::addressof(t), std::addressof(t), sizeof(T)));
     for (unsigned i = 0; i < sizeof(T) / 2; ++i)
         std::swap(bytes[i], bytes[sizeof(T) - 1 - i]);
@@ -135,20 +135,19 @@ struct IsUniquelyRepresented<std::array<T, N>>
     explicit IsUniquelyRepresented() = default;
 };
 
-/**
- * Metafunction returning `true` if the type can be hashed in one call.
- *
- * For `IsContiguouslyHashable<T>::value` to be true, then for every
- * combination of possible values of `T` held in `x` and `y`,
- * if `x == y`, then it must be true that `memcmp(&x, &y, sizeof(T))`
- * return 0; i.e. that `x` and `y` are represented by the same bit pattern.
- *
- * For example:  A two's complement `int` should be contiguously hashable.
- * Every bit pattern produces a unique value that does not compare equal to
- * any other bit pattern's value.  A IEEE floating point should not be
- * contiguously hashable because -0. and 0. have different bit patterns,
- * though they compare equal.
- */
+/** Metafunction returning `true` if the type can be hashed in one call.
+
+    For `IsContiguouslyHashable<T>::value` to be true, then for every
+    combination of possible values of `T` held in `x` and `y`,
+    if `x == y`, then it must be true that `memcmp(&x, &y, sizeof(T))`
+    return 0; i.e. that `x` and `y` are represented by the same bit pattern.
+
+    For example:  A two's complement `int` should be contiguously hashable.
+    Every bit pattern produces a unique value that does not compare equal to
+    any other bit pattern's value.  A IEEE floating point should not be
+    contiguously hashable because -0. and 0. have different bit patterns,
+    though they compare equal.
+*/
 /** @{ */
 template <class T, class HashAlgorithm>
 struct IsContiguouslyHashable
@@ -173,58 +172,54 @@ struct IsContiguouslyHashable<T[N], HashAlgorithm>
 
 //------------------------------------------------------------------------------
 
-/**
- * Logically concatenate input data to a `Hasher`.
- *
- * Hasher requirements:
- *
- *     `X` is the type `Hasher`
- *     `h` is a value of type `x`
- *     `p` is a value convertible to `void const*`
- *     `n` is a value of type `std::size_t`, greater than zero
- *
- *     Expression:
- *         `h.append (p, n);`
- *     Throws:
- *         Never
- *     Effect:
- *         Adds the input data to the hasher state.
- *
- *     Expression:
- *         `static_cast<std::size_t>(j)`
- *     Throws:
- *         Never
- *     Effect:
- *         Returns the resulting hash of all the input data.
- */
+/** Logically concatenate input data to a `Hasher`.
+
+    Hasher requirements:
+
+        `X` is the type `Hasher`
+        `h` is a value of type `x`
+        `p` is a value convertible to `void const*`
+        `n` is a value of type `std::size_t`, greater than zero
+
+        Expression:
+            `h.append (p, n);`
+        Throws:
+            Never
+        Effect:
+            Adds the input data to the hasher state.
+
+        Expression:
+            `static_cast<std::size_t>(j)`
+        Throws:
+            Never
+        Effect:
+            Returns the resulting hash of all the input data.
+*/
 /** @{ */
 
 // scalars
 
 template <class Hasher, class T>
-inline void
+inline std::enable_if_t<IsContiguouslyHashable<T, Hasher>::value>
 hash_append(Hasher& h, T const& t) noexcept
-    requires(IsContiguouslyHashable<T, Hasher>::value)
 {
     // NOLINTNEXTLINE(bugprone-sizeof-expression)
     h(static_cast<void const*>(std::addressof(t)), sizeof(t));
 }
 
 template <class Hasher, class T>
-inline void
+inline std::enable_if_t<
+    !IsContiguouslyHashable<T, Hasher>::value &&
+    (std::is_integral_v<T> || std::is_pointer_v<T> || std::is_enum_v<T>)>
 hash_append(Hasher& h, T t) noexcept
-    requires(
-        !IsContiguouslyHashable<T, Hasher>::value &&
-        (std::is_integral_v<T> || std::is_pointer_v<T> || std::is_enum_v<T>))
 {
     detail::reverseBytes(t);
     h(std::addressof(t), sizeof(t));
 }
 
 template <class Hasher, class T>
-inline void
+inline std::enable_if_t<std::is_floating_point_v<T>>
 hash_append(Hasher& h, T t) noexcept
-    requires(std::is_floating_point_v<T>)
 {
     if (t == 0)
         t = 0;
@@ -244,44 +239,36 @@ hash_append(Hasher& h, std::nullptr_t) noexcept
 // Forward declarations for ADL purposes
 
 template <class Hasher, class T, std::size_t N>
-void
-hash_append(Hasher& h, T (&a)[N]) noexcept
-    requires(!IsContiguouslyHashable<T, Hasher>::value);
+std::enable_if_t<!IsContiguouslyHashable<T, Hasher>::value>
+hash_append(Hasher& h, T (&a)[N]) noexcept;
 
 template <class Hasher, class CharT, class Traits, class Alloc>
-void
-hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept
-    requires(!IsContiguouslyHashable<CharT, Hasher>::value);
+std::enable_if_t<!IsContiguouslyHashable<CharT, Hasher>::value>
+hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept;
 
 template <class Hasher, class CharT, class Traits, class Alloc>
-void
-hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept
-    requires(IsContiguouslyHashable<CharT, Hasher>::value);
+std::enable_if_t<IsContiguouslyHashable<CharT, Hasher>::value>
+hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept;
 
 template <class Hasher, class T, class U>
-void
-hash_append(Hasher& h, std::pair<T, U> const& p) noexcept
-    requires(!IsContiguouslyHashable<std::pair<T, U>, Hasher>::value);
+std::enable_if_t<!IsContiguouslyHashable<std::pair<T, U>, Hasher>::value>
+hash_append(Hasher& h, std::pair<T, U> const& p) noexcept;
 
 template <class Hasher, class T, class Alloc>
-void
-hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
-    requires(!IsContiguouslyHashable<T, Hasher>::value);
+std::enable_if_t<!IsContiguouslyHashable<T, Hasher>::value>
+hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept;
 
 template <class Hasher, class T, class Alloc>
-void
-hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
-    requires(IsContiguouslyHashable<T, Hasher>::value);
+std::enable_if_t<IsContiguouslyHashable<T, Hasher>::value>
+hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept;
 
 template <class Hasher, class T, std::size_t N>
-void
-hash_append(Hasher& h, std::array<T, N> const& a) noexcept
-    requires(!IsContiguouslyHashable<std::array<T, N>, Hasher>::value);
+std::enable_if_t<!IsContiguouslyHashable<std::array<T, N>, Hasher>::value>
+hash_append(Hasher& h, std::array<T, N> const& a) noexcept;
 
 template <class Hasher, class... T>
-void
-hash_append(Hasher& h, std::tuple<T...> const& t) noexcept
-    requires(!IsContiguouslyHashable<std::tuple<T...>, Hasher>::value);
+std::enable_if_t<!IsContiguouslyHashable<std::tuple<T...>, Hasher>::value>
+hash_append(Hasher& h, std::tuple<T...> const& t) noexcept;
 
 template <class Hasher, class Key, class T, class Hash, class Pred, class Alloc>
 void
@@ -292,13 +279,11 @@ void
 hash_append(Hasher& h, std::unordered_set<Key, Hash, Pred, Alloc> const& s);
 
 template <class Hasher, class Key, class Compare, class Alloc>
-void
-hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept
-    requires(!IsContiguouslyHashable<Key, Hasher>::value);
+std::enable_if_t<!IsContiguouslyHashable<Key, Hasher>::value>
+hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept;
 template <class Hasher, class Key, class Compare, class Alloc>
-void
-hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept
-    requires(IsContiguouslyHashable<Key, Hasher>::value);
+std::enable_if_t<IsContiguouslyHashable<Key, Hasher>::value>
+hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept;
 template <class Hasher, class T0, class T1, class... T>
 void
 hash_append(Hasher& h, T0 const& t0, T1 const& t1, T const&... t) noexcept;
@@ -306,9 +291,8 @@ hash_append(Hasher& h, T0 const& t0, T1 const& t1, T const&... t) noexcept;
 // c-array
 
 template <class Hasher, class T, std::size_t N>
-void
+std::enable_if_t<!IsContiguouslyHashable<T, Hasher>::value>
 hash_append(Hasher& h, T (&a)[N]) noexcept
-    requires(!IsContiguouslyHashable<T, Hasher>::value)
 {
     for (auto const& t : a)
         hash_append(h, t);
@@ -317,9 +301,8 @@ hash_append(Hasher& h, T (&a)[N]) noexcept
 // basic_string
 
 template <class Hasher, class CharT, class Traits, class Alloc>
-inline void
+inline std::enable_if_t<!IsContiguouslyHashable<CharT, Hasher>::value>
 hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept
-    requires(!IsContiguouslyHashable<CharT, Hasher>::value)
 {
     for (auto c : s)
         hash_append(h, c);
@@ -327,9 +310,8 @@ hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcep
 }
 
 template <class Hasher, class CharT, class Traits, class Alloc>
-inline void
+inline std::enable_if_t<IsContiguouslyHashable<CharT, Hasher>::value>
 hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept
-    requires(IsContiguouslyHashable<CharT, Hasher>::value)
 {
     h(s.data(), s.size() * sizeof(CharT));
     hash_append(h, s.size());
@@ -338,9 +320,8 @@ hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcep
 // pair
 
 template <class Hasher, class T, class U>
-inline void
+inline std::enable_if_t<!IsContiguouslyHashable<std::pair<T, U>, Hasher>::value>
 hash_append(Hasher& h, std::pair<T, U> const& p) noexcept
-    requires(!IsContiguouslyHashable<std::pair<T, U>, Hasher>::value)
 {
     hash_append(h, p.first, p.second);
 }
@@ -348,9 +329,8 @@ hash_append(Hasher& h, std::pair<T, U> const& p) noexcept
 // vector
 
 template <class Hasher, class T, class Alloc>
-inline void
+inline std::enable_if_t<!IsContiguouslyHashable<T, Hasher>::value>
 hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
-    requires(!IsContiguouslyHashable<T, Hasher>::value)
 {
     for (auto const& t : v)
         hash_append(h, t);
@@ -358,9 +338,8 @@ hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
 }
 
 template <class Hasher, class T, class Alloc>
-inline void
+inline std::enable_if_t<IsContiguouslyHashable<T, Hasher>::value>
 hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
-    requires(IsContiguouslyHashable<T, Hasher>::value)
 {
     h(v.data(), v.size() * sizeof(T));
     hash_append(h, v.size());
@@ -369,37 +348,57 @@ hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
 // array
 
 template <class Hasher, class T, std::size_t N>
-void
+std::enable_if_t<!IsContiguouslyHashable<std::array<T, N>, Hasher>::value>
 hash_append(Hasher& h, std::array<T, N> const& a) noexcept
-    requires(!IsContiguouslyHashable<std::array<T, N>, Hasher>::value)
 {
     for (auto const& t : a)
         hash_append(h, t);
 }
 
 template <class Hasher, class Key, class Compare, class Alloc>
-void
+std::enable_if_t<!IsContiguouslyHashable<Key, Hasher>::value>
 hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept
-    requires(!IsContiguouslyHashable<Key, Hasher>::value)
 {
     for (auto const& t : v)
         hash_append(h, t);
 }
 template <class Hasher, class Key, class Compare, class Alloc>
-void
+std::enable_if_t<IsContiguouslyHashable<Key, Hasher>::value>
 hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept
-    requires(IsContiguouslyHashable<Key, Hasher>::value)
 {
     h(&(v.begin()), v.size() * sizeof(Key));
 }
 // tuple
 
-template <class Hasher, class... T>
+namespace detail {
+
 inline void
-hash_append(Hasher& h, std::tuple<T...> const& t) noexcept
-    requires(!IsContiguouslyHashable<std::tuple<T...>, Hasher>::value)
+forEachItem(...) noexcept
 {
-    std::apply([&h](auto const&... item) { (hash_append(h, item), ...); }, t);
+}
+
+template <class Hasher, class T>
+inline int
+hashOne(Hasher& h, T const& t) noexcept
+{
+    hash_append(h, t);
+    return 0;
+}
+
+template <class Hasher, class... T, std::size_t... I>
+inline void
+tuple_hash(Hasher& h, std::tuple<T...> const& t, std::index_sequence<I...>) noexcept
+{
+    for_each_item(hash_one(h, std::get<I>(t))...);
+}
+
+}  // namespace detail
+
+template <class Hasher, class... T>
+inline std::enable_if_t<!IsContiguouslyHashable<std::tuple<T...>, Hasher>::value>
+hash_append(Hasher& h, std::tuple<T...> const& t) noexcept
+{
+    detail::tuple_hash(h, t, std::index_sequence_for<T...>{});
 }
 
 // shared_ptr

include/xrpl/beast/hash/xxhasher.h

@@ -124,18 +124,14 @@ public:
         }
     }
 
-    template <class Seed>
-    explicit Xxhasher(Seed seed)
-        requires(std::is_unsigned_v<Seed>)
-        : seed_(seed)
+    template <class Seed, std::enable_if_t<std::is_unsigned_v<Seed>>* = nullptr>
+    explicit Xxhasher(Seed seed) : seed_(seed)
     {
         resetBuffers();
     }
 
-    template <class Seed>
-    Xxhasher(Seed seed, Seed)
-        requires(std::is_unsigned_v<Seed>)
-        : seed_(seed)
+    template <class Seed, std::enable_if_t<std::is_unsigned_v<Seed>>* = nullptr>
+    Xxhasher(Seed seed, Seed) : seed_(seed)
     {
         resetBuffers();
     }

include/xrpl/beast/insight/Collector.h

@@ -12,17 +12,16 @@
 
 namespace beast::insight {
 
-/**
- * Interface for a manager that allows collection of metrics.
- *
- * To export metrics from a class, pass and save a shared_ptr to this
- * interface in the class constructor. Create the metric objects
- * as desired (counters, events, gauges, meters, and an optional hook)
- * using the interface.
- *
- * @see Counter, Event, Gauge, Hook, Meter
- * @see NullCollector, StatsDCollector
- */
+/** Interface for a manager that allows collection of metrics.
+
+    To export metrics from a class, pass and save a shared_ptr to this
+    interface in the class constructor. Create the metric objects
+    as desired (counters, events, gauges, meters, and an optional hook)
+    using the interface.
+
+    @see Counter, Event, Gauge, Hook, Meter
+    @see NullCollector, StatsDCollector
+*/
 class Collector
 {
 public:
@@ -30,19 +29,18 @@ public:
 
     virtual ~Collector() = 0;
 
-    /**
-     * Create a hook.
-     *
-     * A hook is called at each collection interval, on an implementation
-     * defined thread. This is a convenience facility for gathering metrics
-     * in the polling style. The typical usage is to update all the metrics
-     * of interest in the handler.
-     *
-     * Handler will be called with this signature:
-     *     void handler (void)
-     *
-     * @see Hook
-     */
+    /** Create a hook.
+
+        A hook is called at each collection interval, on an implementation
+        defined thread. This is a convenience facility for gathering metrics
+        in the polling style. The typical usage is to update all the metrics
+        of interest in the handler.
+
+        Handler will be called with this signature:
+            void handler (void)
+
+        @see Hook
+    */
     /** @{ */
     template <class Handler>
     Hook
@@ -55,10 +53,9 @@ public:
     makeHook(HookImpl::HandlerType const& handler) = 0;
     /** @} */
 
-    /**
-     * Create a counter with the specified name.
-     * @see Counter
-     */
+    /** Create a counter with the specified name.
+        @see Counter
+    */
     /** @{ */
     virtual Counter
     makeCounter(std::string const& name) = 0;
@@ -72,10 +69,9 @@ public:
     }
     /** @} */
 
-    /**
-     * Create an event with the specified name.
-     * @see Event
-     */
+    /** Create an event with the specified name.
+        @see Event
+    */
     /** @{ */
     virtual Event
     makeEvent(std::string const& name) = 0;
@@ -89,10 +85,9 @@ public:
     }
     /** @} */
 
-    /**
-     * Create a gauge with the specified name.
-     * @see Gauge
-     */
+    /** Create a gauge with the specified name.
+        @see Gauge
+    */
     /** @{ */
     virtual Gauge
     makeGauge(std::string const& name) = 0;
@@ -106,10 +101,9 @@ public:
     }
     /** @} */
 
-    /**
-     * Create a meter with the specified name.
-     * @see Meter
-     */
+    /** Create a meter with the specified name.
+        @see Meter
+    */
     /** @{ */
     virtual Meter
     makeMeter(std::string const& name) = 0;

include/xrpl/beast/insight/Counter.h

@@ -7,39 +7,34 @@
 
 namespace beast::insight {
 
-/**
- * A metric for measuring an integral value.
- *
- * A counter is a gauge calculated at the server. The owner of the counter
- * may increment and decrement the value by an amount.
- *
- * This is a lightweight reference wrapper which is cheap to copy and assign.
- * When the last reference goes away, the metric is no longer collected.
- */
+/** A metric for measuring an integral value.
+
+    A counter is a gauge calculated at the server. The owner of the counter
+    may increment and decrement the value by an amount.
+
+    This is a lightweight reference wrapper which is cheap to copy and assign.
+    When the last reference goes away, the metric is no longer collected.
+*/
 class Counter final
 {
 public:
     using value_type = CounterImpl::value_type;
 
-    /**
-     * Create a null metric.
-     * A null metric reports no information.
-     */
+    /** Create a null metric.
+        A null metric reports no information.
+    */
     Counter() = default;
 
-    /**
-     * Create the metric reference the specified implementation.
-     * Normally this won't be called directly. Instead, call the appropriate
-     * factory function in the Collector interface.
-     * @see Collector.
-     */
+    /** Create the metric reference the specified implementation.
+        Normally this won't be called directly. Instead, call the appropriate
+        factory function in the Collector interface.
+        @see Collector.
+    */
     explicit Counter(std::shared_ptr<CounterImpl> impl) : impl_(std::move(impl))
     {
     }
 
-    /**
-     * Increment the counter.
-     */
+    /** Increment the counter. */
     /** @{ */
     void
     increment(value_type amount) const

include/xrpl/beast/insight/Event.h

@@ -8,40 +8,35 @@
 
 namespace beast::insight {
 
-/**
- * A metric for reporting event timing.
- *
- * An event is an operation that has an associated millisecond time, or
- * other integral value. Because events happen at a specific moment, the
- * metric only supports a push-style interface.
- *
- * This is a lightweight reference wrapper which is cheap to copy and assign.
- * When the last reference goes away, the metric is no longer collected.
- */
+/** A metric for reporting event timing.
+
+    An event is an operation that has an associated millisecond time, or
+    other integral value. Because events happen at a specific moment, the
+    metric only supports a push-style interface.
+
+    This is a lightweight reference wrapper which is cheap to copy and assign.
+    When the last reference goes away, the metric is no longer collected.
+*/
 class Event final
 {
 public:
     using value_type = EventImpl::value_type;
 
-    /**
-     * Create a null metric.
-     * A null metric reports no information.
-     */
+    /** Create a null metric.
+        A null metric reports no information.
+    */
     Event() = default;
 
-    /**
-     * Create the metric reference the specified implementation.
-     * Normally this won't be called directly. Instead, call the appropriate
-     * factory function in the Collector interface.
-     * @see Collector.
-     */
+    /** Create the metric reference the specified implementation.
+        Normally this won't be called directly. Instead, call the appropriate
+        factory function in the Collector interface.
+        @see Collector.
+    */
     explicit Event(std::shared_ptr<EventImpl> impl) : impl_(std::move(impl))
     {
     }
 
-    /**
-     * Push an event notification.
-     */
+    /** Push an event notification. */
     template <class Rep, class Period>
     void
     notify(std::chrono::duration<Rep, Period> const& value) const

include/xrpl/beast/insight/Gauge.h

@@ -7,44 +7,40 @@
 
 namespace beast::insight {
 
-/**
- * A metric for measuring an integral value.
- *
- * A gauge is an instantaneous measurement of a value, like the gas gauge
- * in a car. The caller directly sets the value, or adjusts it by a
- * specified amount. The value is kept in the client rather than the collector.
- *
- * This is a lightweight reference wrapper which is cheap to copy and assign.
- * When the last reference goes away, the metric is no longer collected.
- */
+/** A metric for measuring an integral value.
+
+    A gauge is an instantaneous measurement of a value, like the gas gauge
+    in a car. The caller directly sets the value, or adjusts it by a
+    specified amount. The value is kept in the client rather than the collector.
+
+    This is a lightweight reference wrapper which is cheap to copy and assign.
+    When the last reference goes away, the metric is no longer collected.
+*/
 class Gauge final
 {
 public:
     using value_type = GaugeImpl::value_type;
     using difference_type = GaugeImpl::difference_type;
 
-    /**
-     * Create a null metric.
-     * A null metric reports no information.
-     */
+    /** Create a null metric.
+        A null metric reports no information.
+    */
     Gauge() = default;
 
-    /**
-     * Create the metric reference the specified implementation.
-     * Normally this won't be called directly. Instead, call the appropriate
-     * factory function in the Collector interface.
-     * @see Collector.
-     */
+    /** Create the metric reference the specified implementation.
+        Normally this won't be called directly. Instead, call the appropriate
+        factory function in the Collector interface.
+        @see Collector.
+    */
     explicit Gauge(std::shared_ptr<GaugeImpl> impl) : impl_(std::move(impl))
     {
     }
 
-    /**
-     * Set the value on the gauge.
-     * A Collector implementation should combine multiple calls to value
-     * changes into a single change if the calls occur within a single
-     * collection interval.
-     */
+    /** Set the value on the gauge.
+        A Collector implementation should combine multiple calls to value
+        changes into a single change if the calls occur within a single
+        collection interval.
+    */
     /** @{ */
     void
     set(value_type value) const
@@ -53,11 +49,6 @@ public:
             impl_->set(value);
     }
 
-    // This is a write-through handle: assignment sets the value of the
-    // referenced metric.  It is const-qualified and returns Gauge const&
-    // (a non-const Gauge& would require a const_cast), so it does not follow
-    // the conventional assignment-operator signature.
-    // NOLINTNEXTLINE(misc-unconventional-assign-operator)
     Gauge const&
     operator=(value_type value) const
     {
@@ -66,9 +57,7 @@ public:
     }
     /** @} */
 
-    /**
-     * Adjust the value of the gauge.
-     */
+    /** Adjust the value of the gauge. */
     /** @{ */
     void
     increment(difference_type amount) const

include/xrpl/beast/insight/Group.h

@@ -7,17 +7,13 @@
 
 namespace beast::insight {
 
-/**
- * A collector front-end that manages a group of metrics.
- */
+/** A collector front-end that manages a group of metrics. */
 class Group : public Collector
 {
 public:
     using ptr = std::shared_ptr<Group>;
 
-    /**
-     * Returns the name of this group, for diagnostics.
-     */
+    /** Returns the name of this group, for diagnostics. */
     [[nodiscard]] virtual std::string const&
     name() const = 0;
 };

include/xrpl/beast/insight/Groups.h

@@ -8,17 +8,13 @@
 
 namespace beast::insight {
 
-/**
- * A container for managing a set of metric groups.
- */
+/** A container for managing a set of metric groups. */
 class Groups
 {
 public:
     virtual ~Groups() = 0;
 
-    /**
-     * Find or create a new collector with a given name.
-     */
+    /** Find or create a new collector with a given name. */
     /** @{ */
     virtual Group::ptr const&
     get(std::string const& name) = 0;
@@ -31,9 +27,7 @@ public:
     /** @} */
 };
 
-/**
- * Create a group container that uses the specified collector.
- */
+/** Create a group container that uses the specified collector. */
 std::unique_ptr<Groups>
 makeGroups(Collector::ptr const& collector);
 

include/xrpl/beast/insight/Hook.h

@@ -7,24 +7,20 @@
 
 namespace beast::insight {
 
-/**
- * A reference to a handler for performing polled collection.
- */
+/** A reference to a handler for performing polled collection. */
 class Hook final
 {
 public:
-    /**
-     * Create a null hook.
-     * A null hook has no associated handler.
-     */
+    /** Create a null hook.
+        A null hook has no associated handler.
+    */
     Hook() = default;
 
-    /**
-     * Create a hook referencing the specified implementation.
-     * Normally this won't be called directly. Instead, call the appropriate
-     * factory function in the Collector interface.
-     * @see Collector.
-     */
+    /** Create a hook referencing the specified implementation.
+        Normally this won't be called directly. Instead, call the appropriate
+        factory function in the Collector interface.
+        @see Collector.
+    */
     explicit Hook(std::shared_ptr<HookImpl> impl) : impl_(std::move(impl))
     {
     }

include/xrpl/beast/insight/Meter.h

@@ -7,38 +7,33 @@
 
 namespace beast::insight {
 
-/**
- * A metric for measuring an integral value.
- *
- * A meter may be thought of as an increment-only counter.
- *
- * This is a lightweight reference wrapper which is cheap to copy and assign.
- * When the last reference goes away, the metric is no longer collected.
- */
+/** A metric for measuring an integral value.
+
+    A meter may be thought of as an increment-only counter.
+
+    This is a lightweight reference wrapper which is cheap to copy and assign.
+    When the last reference goes away, the metric is no longer collected.
+*/
 class Meter final
 {
 public:
     using value_type = MeterImpl::value_type;
 
-    /**
-     * Create a null metric.
-     * A null metric reports no information.
-     */
+    /** Create a null metric.
+        A null metric reports no information.
+    */
     Meter() = default;
 
-    /**
-     * Create the metric reference the specified implementation.
-     * Normally this won't be called directly. Instead, call the appropriate
-     * factory function in the Collector interface.
-     * @see Collector.
-     */
+    /** Create the metric reference the specified implementation.
+        Normally this won't be called directly. Instead, call the appropriate
+        factory function in the Collector interface.
+        @see Collector.
+    */
     explicit Meter(std::shared_ptr<MeterImpl> impl) : impl_(std::move(impl))
     {
     }
 
-    /**
-     * Increment the meter.
-     */
+    /** Increment the meter. */
     /** @{ */
     void
     increment(value_type amount) const

include/xrpl/beast/insight/NullCollector.h

@@ -6,9 +6,7 @@
 
 namespace beast::insight {
 
-/**
- * A Collector which does not collect metrics.
- */
+/** A Collector which does not collect metrics. */
 class NullCollector : public Collector
 {
 public:

include/xrpl/beast/insight/StatsDCollector.h

@@ -9,22 +9,20 @@
 
 namespace beast::insight {
 
-/**
- * A Collector that reports metrics to a StatsD server.
- * Reference:
- *     https://github.com/b/statsd_spec
- */
+/** A Collector that reports metrics to a StatsD server.
+    Reference:
+        https://github.com/b/statsd_spec
+*/
 class StatsDCollector : public Collector
 {
 public:
     explicit StatsDCollector() = default;
 
-    /**
-     * Create a StatsD collector.
-     * @param address The IP address and port of the StatsD server.
-     * @param prefix A string pre-pended before each metric name.
-     * @param journal Destination for logging output.
-     */
+    /** Create a StatsD collector.
+        @param address The IP address and port of the StatsD server.
+        @param prefix A string pre-pended before each metric name.
+        @param journal Destination for logging output.
+    */
     static std::shared_ptr<StatsDCollector>
     make(IP::Endpoint const& address, std::string const& prefix, Journal journal);
 };

include/xrpl/beast/net/IPAddress.h

@@ -19,54 +19,42 @@ namespace IP {
 
 using Address = boost::asio::ip::address;
 
-/**
- * Returns the address represented as a string.
- */
+/** Returns the address represented as a string. */
 inline std::string
 to_string(Address const& addr)
 {
     return addr.to_string();
 }
 
-/**
- * Returns `true` if this is a loopback address.
- */
+/** Returns `true` if this is a loopback address. */
 inline bool
 isLoopback(Address const& addr)
 {
     return addr.is_loopback();
 }
 
-/**
- * Returns `true` if the address is unspecified.
- */
+/** Returns `true` if the address is unspecified. */
 inline bool
 isUnspecified(Address const& addr)
 {
     return addr.is_unspecified();
 }
 
-/**
- * Returns `true` if the address is a multicast address.
- */
+/** Returns `true` if the address is a multicast address. */
 inline bool
 isMulticast(Address const& addr)
 {
     return addr.is_multicast();
 }
 
-/**
- * Returns `true` if the address is a private unroutable address.
- */
+/** Returns `true` if the address is a private unroutable address. */
 inline bool
 isPrivate(Address const& addr)
 {
     return (addr.is_v4()) ? isPrivate(addr.to_v4()) : isPrivate(addr.to_v6());
 }
 
-/**
- * Returns `true` if the address is a public routable address.
- */
+/** Returns `true` if the address is a public routable address. */
 inline bool
 isPublic(Address const& addr)
 {

include/xrpl/beast/net/IPAddressConversion.h

@@ -6,29 +6,23 @@
 
 namespace beast::IP {
 
-/**
- * Convert to Endpoint.
- * The port is set to zero.
- */
+/** Convert to Endpoint.
+    The port is set to zero.
+*/
 Endpoint
 fromAsio(boost::asio::ip::address const& address);
 
-/**
- * Convert to Endpoint.
- */
+/** Convert to Endpoint. */
 Endpoint
 fromAsio(boost::asio::ip::tcp::endpoint const& endpoint);
 
-/**
- * Convert to asio::ip::address.
- * The port is ignored.
- */
+/** Convert to asio::ip::address.
+    The port is ignored.
+*/
 boost::asio::ip::address
 toAsioAddress(Endpoint const& endpoint);
 
-/**
- * Convert to asio::ip::tcp::endpoint.
- */
+/** Convert to asio::ip::tcp::endpoint. */
 boost::asio::ip::tcp::endpoint
 toAsioEndpoint(Endpoint const& endpoint);
 

include/xrpl/beast/net/IPAddressV4.h

@@ -6,22 +6,17 @@ namespace beast::IP {
 
 using AddressV4 = boost::asio::ip::address_v4;
 
-/**
- * Returns `true` if the address is a private unroutable address.
- */
+/** Returns `true` if the address is a private unroutable address. */
 bool
 isPrivate(AddressV4 const& addr);
 
-/**
- * Returns `true` if the address is a public routable address.
- */
+/** Returns `true` if the address is a public routable address. */
 bool
 isPublic(AddressV4 const& addr);
 
-/**
- * Returns the address class for the given address.
- * @note Class 'D' represents multicast addresses (224.*.*.*).
- */
+/** Returns the address class for the given address.
+    @note Class 'D' represents multicast addresses (224.*.*.*).
+*/
 char
 getClass(AddressV4 const& address);
 

include/xrpl/beast/net/IPAddressV6.h

@@ -6,15 +6,11 @@ namespace beast::IP {
 
 using AddressV6 = boost::asio::ip::address_v6;
 
-/**
- * Returns `true` if the address is a private unroutable address.
- */
+/** Returns `true` if the address is a private unroutable address. */
 bool
 isPrivate(AddressV6 const& addr);
 
-/**
- * Returns `true` if the address is a public routable address.
- */
+/** Returns `true` if the address is a public routable address. */
 bool
 isPublic(AddressV6 const& addr);
 

include/xrpl/beast/net/IPEndpoint.h

@@ -17,68 +17,51 @@ namespace beast::IP {
 
 using Port = std::uint16_t;
 
-/**
- * A version-independent IP address and port combination.
- */
+/** A version-independent IP address and port combination. */
 class Endpoint
 {
 public:
-    /**
-     * Create an unspecified endpoint.
-     */
+    /** Create an unspecified endpoint. */
     Endpoint();
 
-    /**
-     * Create an endpoint from the address and optional port.
-     */
+    /** Create an endpoint from the address and optional port. */
     explicit Endpoint(Address addr, Port port = 0);
 
-    /**
-     * Create an Endpoint from a string.
-     * If the port is omitted, the endpoint will have a zero port.
-     * @return An optional endpoint; will be `std::nullopt` on failure
-     */
+    /** Create an Endpoint from a string.
+        If the port is omitted, the endpoint will have a zero port.
+        @return An optional endpoint; will be `std::nullopt` on failure
+    */
     static std::optional<Endpoint>
     fromStringChecked(std::string const& s);
     static Endpoint
     fromString(std::string const& s);
 
-    /**
-     * Returns a string representing the endpoint.
-     */
+    /** Returns a string representing the endpoint. */
     [[nodiscard]] std::string
     toString() const;
 
-    /**
-     * Returns the port number on the endpoint.
-     */
+    /** Returns the port number on the endpoint. */
     [[nodiscard]] Port
     port() const
     {
         return port_;
     }
 
-    /**
-     * Returns a new Endpoint with a different port.
-     */
+    /** Returns a new Endpoint with a different port. */
     [[nodiscard]] Endpoint
     atPort(Port port) const
     {
         return Endpoint(addr_, port);
     }
 
-    /**
-     * Returns the address portion of this endpoint.
-     */
+    /** Returns the address portion of this endpoint. */
     [[nodiscard]] Address const&
     address() const
     {
         return addr_;
     }
 
-    /**
-     * Convenience accessors for the address part.
-     */
+    /** Convenience accessors for the address part. */
     /** @{ */
     [[nodiscard]] bool
     isV4() const
@@ -102,9 +85,7 @@ public:
     }
     /** @} */
 
-    /**
-     * Arithmetic comparison.
-     */
+    /** Arithmetic comparison. */
     /** @{ */
     friend bool
     operator==(Endpoint const& lhs, Endpoint const& rhs);
@@ -150,45 +131,35 @@ private:
 
 // Properties
 
-/**
- * Returns `true` if the endpoint is a loopback address.
- */
+/** Returns `true` if the endpoint is a loopback address. */
 inline bool
 isLoopback(Endpoint const& endpoint)
 {
     return isLoopback(endpoint.address());
 }
 
-/**
- * Returns `true` if the endpoint is unspecified.
- */
+/** Returns `true` if the endpoint is unspecified. */
 inline bool
 isUnspecified(Endpoint const& endpoint)
 {
     return isUnspecified(endpoint.address());
 }
 
-/**
- * Returns `true` if the endpoint is a multicast address.
- */
+/** Returns `true` if the endpoint is a multicast address. */
 inline bool
 isMulticast(Endpoint const& endpoint)
 {
     return isMulticast(endpoint.address());
 }
 
-/**
- * Returns `true` if the endpoint is a private unroutable address.
- */
+/** Returns `true` if the endpoint is a private unroutable address. */
 inline bool
 isPrivate(Endpoint const& endpoint)
 {
     return isPrivate(endpoint.address());
 }
 
-/**
- * Returns `true` if the endpoint is a public routable address.
- */
+/** Returns `true` if the endpoint is a public routable address. */
 inline bool
 isPublic(Endpoint const& endpoint)
 {
@@ -197,18 +168,14 @@ isPublic(Endpoint const& endpoint)
 
 //------------------------------------------------------------------------------
 
-/**
- * Returns the endpoint represented as a string.
- */
+/** Returns the endpoint represented as a string. */
 inline std::string
 to_string(Endpoint const& endpoint)
 {
     return endpoint.toString();
 }
 
-/**
- * Output stream conversion.
- */
+/** Output stream conversion. */
 template <typename OutputStream>
 OutputStream&
 operator<<(OutputStream& os, Endpoint const& endpoint)
@@ -217,9 +184,7 @@ operator<<(OutputStream& os, Endpoint const& endpoint)
     return os;
 }
 
-/**
- * Input stream conversion.
- */
+/** Input stream conversion. */
 std::istream&
 operator>>(std::istream& is, Endpoint& endpoint);
 
@@ -228,9 +193,7 @@ operator>>(std::istream& is, Endpoint& endpoint);
 //------------------------------------------------------------------------------
 
 namespace std {
-/**
- * std::hash support.
- */
+/** std::hash support. */
 template <>
 struct hash<::beast::IP::Endpoint>
 {
@@ -245,9 +208,7 @@ struct hash<::beast::IP::Endpoint>
 }  // namespace std
 
 namespace boost {
-/**
- * boost::hash support.
- */
+/** boost::hash support. */
 template <>
 struct hash<::beast::IP::Endpoint>
 {

include/xrpl/beast/rfc2616.h

@@ -30,20 +30,17 @@ struct CiEqualPred
     }
 };
 
-/**
- * Returns `true` if `c` is linear white space.
- *
- * This excludes the CRLF sequence allowed for line continuations.
- */
+/** Returns `true` if `c` is linear white space.
+
+    This excludes the CRLF sequence allowed for line continuations.
+*/
 inline bool
 isLws(char c)
 {
     return c == ' ' || c == '\t';
 }
 
-/**
- * Returns `true` if `c` is any whitespace character.
- */
+/** Returns `true` if `c` is any whitespace character. */
 inline bool
 isWhite(char c)
 {
@@ -90,15 +87,14 @@ trimRight(String const& s)
 
 }  // namespace detail
 
-/**
- * Parse a character sequence of values separated by commas.
- * Double quotes and escape sequences will be converted.  Excess white
- * space, commas, double quotes, and empty elements are not copied.
- * Format:
- *    #(token|quoted-string)
- * Reference:
- *     http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2
- */
+/** Parse a character sequence of values separated by commas.
+    Double quotes and escape sequences will be converted.  Excess white
+    space, commas, double quotes, and empty elements are not copied.
+    Format:
+       #(token|quoted-string)
+    Reference:
+        http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2
+*/
 template <
     class FwdIt,
     class Result = std::vector<std::basic_string<typename std::iterator_traits<FwdIt>::value_type>>,
@@ -193,15 +189,14 @@ splitCommas(boost::beast::string_view const& s)
 
 //------------------------------------------------------------------------------
 
-/**
- * Iterates through a comma separated list.
- *
- * Meets the requirements of ForwardIterator.
- *
- * List defined in rfc2616 2.1.
- *
- * @note Values returned may contain backslash escapes.
- */
+/** Iterates through a comma separated list.
+
+    Meets the requirements of ForwardIterator.
+
+    List defined in rfc2616 2.1.
+
+    @note Values returned may contain backslash escapes.
+*/
 class ListIterator
 {
     using iter_type = boost::string_ref::const_iterator;
@@ -328,20 +323,17 @@ ListIterator::increment()
         }
     }
 }
-/**
- * Returns true if two strings are equal.
- *
- * A case-insensitive comparison is used.
- */
+/** Returns true if two strings are equal.
+
+    A case-insensitive comparison is used.
+*/
 inline bool
 ciEqual(boost::string_ref s1, boost::string_ref s2)
 {
     return boost::range::equal(s1, s2, detail::CiEqualPred{});
 }
 
-/**
- * Returns a range representing the list.
- */
+/** Returns a range representing the list. */
 inline boost::iterator_range<ListIterator>
 makeList(boost::string_ref const& field)
 {
@@ -349,11 +341,10 @@ makeList(boost::string_ref const& field)
         ListIterator{field.begin(), field.end()}, ListIterator{field.end(), field.end()}};
 }
 
-/**
- * Returns true if the specified token exists in the list.
- *
- * A case-insensitive comparison is used.
- */
+/** Returns true if the specified token exists in the list.
+
+    A case-insensitive comparison is used.
+*/
 template <class = void>
 bool
 tokenInList(boost::string_ref const& value, boost::string_ref const& token)

include/xrpl/beast/test/yield_to.h

@@ -19,13 +19,12 @@
 
 namespace beast::test {
 
-/**
- * Mix-in to support tests using asio coroutines.
- *
- * Derive from this class and use yield_to to launch test
- * functions inside coroutines. This is handy for testing
- * asynchronous asio code.
- */
+/** Mix-in to support tests using asio coroutines.
+
+    Derive from this class and use yield_to to launch test
+    functions inside coroutines. This is handy for testing
+    asynchronous asio code.
+*/
 class EnableYieldTo
 {
 protected:
@@ -39,9 +38,7 @@ private:
     std::size_t running_ = 0;
 
 public:
-    /**
-     * The type of yield context passed to functions.
-     */
+    /// The type of yield context passed to functions.
     using yield_context = boost::asio::yield_context;
 
     explicit EnableYieldTo(std::size_t concurrency = 1) : work_(boost::asio::make_work_guard(ios_))
@@ -60,27 +57,24 @@ public:
             t.join();
     }
 
-    /**
-     * Return the `io_context` associated with the object
-     */
+    /// Return the `io_context` associated with the object
     boost::asio::io_context&
     getIoContext()
     {
         return ios_;
     }
 
-    /**
-     * Run one or more functions, each in a coroutine.
-     *
-     * This call will block until all coroutines terminate.
-     *
-     * Each functions should have this signature:
-     * @code
-     *     void f(yield_context);
-     * @endcode
-     *
-     * @param fn... One or more functions to invoke.
-     */
+    /** Run one or more functions, each in a coroutine.
+
+        This call will block until all coroutines terminate.
+
+        Each functions should have this signature:
+        @code
+            void f(yield_context);
+        @endcode
+
+        @param fn... One or more functions to invoke.
+    */
 #if BEAST_DOXYGEN
     template <class... FN>
     void

include/xrpl/beast/type_name.h

@@ -23,7 +23,6 @@ typeName()
     if (auto s = abi::__cxa_demangle(name.c_str(), nullptr, nullptr, nullptr))
     {
         name = s;
-        // NOLINTNEXTLINE(cppcoreguidelines-no-malloc)
         std::free(s);
     }
 #endif

include/xrpl/beast/unit_test/amount.h

@@ -10,9 +10,7 @@
 
 namespace beast::unit_test {
 
-/**
- * Utility for producing nicely composed output of amounts with units.
- */
+/** Utility for producing nicely composed output of amounts with units. */
 class Amount
 {
 private:

include/xrpl/beast/unit_test/detail/const_container.h

@@ -6,11 +6,10 @@
 
 namespace beast::unit_test::detail {
 
-/**
- * Adapter to constrain a container interface.
- * The interface allows for limited read only operations. Derived classes
- * provide additional behavior.
- */
+/** Adapter to constrain a container interface.
+    The interface allows for limited read only operations. Derived classes
+    provide additional behavior.
+*/
 template <class Container>
 class ConstContainer
 {
@@ -39,27 +38,21 @@ public:
     using iterator = cont_type::const_iterator;
     using const_iterator = cont_type::const_iterator;
 
-    /**
-     * Returns `true` if the container is empty.
-     */
+    /** Returns `true` if the container is empty. */
     [[nodiscard]] bool
     empty() const
     {
         return cont_.empty();
     }
 
-    /**
-     * Returns the number of items in the container.
-     */
+    /** Returns the number of items in the container. */
     [[nodiscard]] size_type
     size() const
     {
         return cont_.size();
     }
 
-    /**
-     * Returns forward iterators for traversal.
-     */
+    /** Returns forward iterators for traversal. */
     /** @{ */
     [[nodiscard]] const_iterator
     begin() const

include/xrpl/beast/unit_test/global_suites.h

@@ -10,9 +10,7 @@ namespace beast::unit_test {
 
 namespace detail {
 
-/**
- * Holds test suites registered during static initialization.
- */
+/// Holds test suites registered during static initialization.
 inline SuiteList&
 globalSuites()
 {
@@ -36,9 +34,7 @@ struct InsertSuite
 
 }  // namespace detail
 
-/**
- * Holds test suites registered during static initialization.
- */
+/// Holds test suites registered during static initialization.
 inline SuiteList const&
 globalSuites()
 {

include/xrpl/beast/unit_test/match.h

@@ -121,48 +121,42 @@ Selector::operator()(SuiteInfo const& s)
 
 // Utility functions for producing predicates to select suites.
 
-/**
- * Returns a predicate that implements a smart matching rule.
- * The predicate checks the suite, module, and library fields of the
- * SuiteInfo in that order. When it finds a match, it changes modes
- * depending on what was found:
- *
- *     If a suite is matched first, then only the suite is selected. The
- *     suite may be marked manual.
- *
- *     If a module is matched first, then only suites from that module
- *     and library not marked manual are selected from then on.
- *
- *     If a library is matched first, then only suites from that library
- *     not marked manual are selected from then on.
- */
+/** Returns a predicate that implements a smart matching rule.
+    The predicate checks the suite, module, and library fields of the
+    SuiteInfo in that order. When it finds a match, it changes modes
+    depending on what was found:
+
+        If a suite is matched first, then only the suite is selected. The
+        suite may be marked manual.
+
+        If a module is matched first, then only suites from that module
+        and library not marked manual are selected from then on.
+
+        If a library is matched first, then only suites from that library
+        not marked manual are selected from then on.
+
+*/
 inline Selector
 matchAuto(std::string const& name)
 {
     return Selector(Selector::ModeT::Automatch, name);
 }
 
-/**
- * Return a predicate that matches all suites not marked manual.
- */
+/** Return a predicate that matches all suites not marked manual. */
 inline Selector
 matchAll()
 {
     return Selector(Selector::ModeT::All);
 }
 
-/**
- * Returns a predicate that matches a specific suite.
- */
+/** Returns a predicate that matches a specific suite. */
 inline Selector
 matchSuite(std::string const& name)
 {
     return Selector(Selector::ModeT::Suite, name);
 }
 
-/**
- * Returns a predicate that matches all suites in a library.
- */
+/** Returns a predicate that matches all suites in a library. */
 inline Selector
 matchLibrary(std::string const& name)
 {

include/xrpl/beast/unit_test/recorder.h

@@ -13,9 +13,7 @@
 
 namespace beast::unit_test {
 
-/**
- * A test runner that stores the results.
- */
+/** A test runner that stores the results. */
 class Recorder : public Runner
 {
 private:
@@ -26,9 +24,7 @@ private:
 public:
     Recorder() = default;
 
-    /**
-     * Returns a report with the results of all completed suites.
-     */
+    /** Returns a report with the results of all completed suites. */
     [[nodiscard]] Results const&
     report() const
     {

include/xrpl/beast/unit_test/reporter.h

@@ -25,10 +25,9 @@ namespace beast::unit_test {
 
 namespace detail {
 
-/**
- * A simple test runner that writes everything to a stream in real time.
- * The totals are output when the object is destroyed.
- */
+/** A simple test runner that writes everything to a stream in real time.
+    The totals are output when the object is destroyed.
+*/
 template <class = void>
 class Reporter : public Runner
 {

include/xrpl/beast/unit_test/results.h

@@ -13,15 +13,11 @@
 
 namespace beast::unit_test {
 
-/**
- * Holds a set of test condition outcomes in a testcase.
- */
+/** Holds a set of test condition outcomes in a testcase. */
 class CaseResults
 {
 public:
-    /**
-     * Holds the result of evaluating one test condition.
-     */
+    /** Holds the result of evaluating one test condition. */
     struct Test
     {
         explicit Test(bool pass) : pass(pass)
@@ -45,36 +41,28 @@ private:
     public:
         TestsT() = default;
 
-        /**
-         * Returns the total number of test conditions.
-         */
+        /** Returns the total number of test conditions. */
         [[nodiscard]] std::size_t
         total() const
         {
             return cont().size();
         }
 
-        /**
-         * Returns the number of failed test conditions.
-         */
+        /** Returns the number of failed test conditions. */
         [[nodiscard]] std::size_t
         failed() const
         {
             return failed_;
         }
 
-        /**
-         * Register a successful test condition.
-         */
+        /** Register a successful test condition. */
         void
         pass()
         {
             cont().emplace_back(true);
         }
 
-        /**
-         * Register a failed test condition.
-         */
+        /** Register a failed test condition. */
         void
         fail(std::string const& reason = "")
         {
@@ -86,9 +74,7 @@ private:
     class LogT : public detail::ConstContainer<std::vector<std::string>>
     {
     public:
-        /**
-         * Insert a string into the log.
-         */
+        /** Insert a string into the log. */
         void
         insert(std::string const& s)
         {
@@ -103,31 +89,23 @@ public:
     {
     }
 
-    /**
-     * Returns the name of this testcase.
-     */
+    /** Returns the name of this testcase. */
     [[nodiscard]] std::string const&
     name() const
     {
         return name_;
     }
 
-    /**
-     * Memberspace for a container of test condition outcomes.
-     */
+    /** Memberspace for a container of test condition outcomes. */
     TestsT tests;
 
-    /**
-     * Memberspace for a container of testcase log messages.
-     */
+    /** Memberspace for a container of testcase log messages. */
     LogT log;
 };
 
 //--------------------------------------------------------------------------
 
-/**
- * Holds the set of testcase results in a suite.
- */
+/** Holds the set of testcase results in a suite. */
 class SuiteResults : public detail::ConstContainer<std::vector<CaseResults>>
 {
 private:
@@ -140,36 +118,28 @@ public:
     {
     }
 
-    /**
-     * Returns the name of this suite.
-     */
+    /** Returns the name of this suite. */
     [[nodiscard]] std::string const&
     name() const
     {
         return name_;
     }
 
-    /**
-     * Returns the total number of test conditions.
-     */
+    /** Returns the total number of test conditions. */
     [[nodiscard]] std::size_t
     total() const
     {
         return total_;
     }
 
-    /**
-     * Returns the number of failures.
-     */
+    /** Returns the number of failures. */
     [[nodiscard]] std::size_t
     failed() const
     {
         return failed_;
     }
 
-    /**
-     * Insert a set of testcase results.
-     */
+    /** Insert a set of testcase results. */
     /** @{ */
     void
     insert(CaseResults&& r)
@@ -192,9 +162,7 @@ public:
 //------------------------------------------------------------------------------
 
 // VFALCO TODO Make this a template class using scoped allocators
-/**
- * Holds the results of running a set of testsuites.
- */
+/** Holds the results of running a set of testsuites. */
 class Results : public detail::ConstContainer<std::vector<SuiteResults>>
 {
 private:
@@ -205,36 +173,28 @@ private:
 public:
     Results() = default;
 
-    /**
-     * Returns the total number of test cases.
-     */
+    /** Returns the total number of test cases. */
     [[nodiscard]] std::size_t
     cases() const
     {
         return cases_;
     }
 
-    /**
-     * Returns the total number of test conditions.
-     */
+    /** Returns the total number of test conditions. */
     [[nodiscard]] std::size_t
     total() const
     {
         return total_;
     }
 
-    /**
-     * Returns the number of failures.
-     */
+    /** Returns the number of failures. */
     [[nodiscard]] std::size_t
     failed() const
     {
         return failed_;
     }
 
-    /**
-     * Insert a set of suite results.
-     */
+    /** Insert a set of suite results. */
     /** @{ */
     void
     insert(SuiteResults&& r)

include/xrpl/beast/unit_test/runner.h

@@ -13,12 +13,11 @@
 
 namespace beast::unit_test {
 
-/**
- * Unit test runner interface.
- *
- * Derived classes can customize the reporting behavior. This interface is
- * injected into the unit_test class to receive the results of the tests.
- */
+/** Unit test runner interface.
+
+    Derived classes can customize the reporting behavior. This interface is
+    injected into the unit_test class to receive the results of the tests.
+*/
 class Runner
 {
     std::string arg_;
@@ -34,132 +33,110 @@ public:
     Runner&
     operator=(Runner const&) = delete;
 
-    /**
-     * Set the argument string.
-     *
-     * The argument string is available to suites and
-     * allows for customization of the test. Each suite
-     * defines its own syntax for the argument string.
-     * The same argument is passed to all suites.
-     */
+    /** Set the argument string.
+
+        The argument string is available to suites and
+        allows for customization of the test. Each suite
+        defines its own syntax for the argument string.
+        The same argument is passed to all suites.
+    */
     void
     arg(std::string const& s)
     {
         arg_ = s;
     }
 
-    /**
-     * Returns the argument string.
-     */
+    /** Returns the argument string. */
     [[nodiscard]] std::string const&
     arg() const
     {
         return arg_;
     }
 
-    /**
-     * Run the specified suite.
-     * @return `true` if any conditions failed.
-     */
+    /** Run the specified suite.
+        @return `true` if any conditions failed.
+    */
     template <class = void>
     bool
     run(SuiteInfo const& s);
 
-    /**
-     * Run a sequence of suites.
-     * The expression
-     *     `FwdIter::value_type`
-     * must be convertible to `SuiteInfo`.
-     * @return `true` if any conditions failed.
-     */
+    /** Run a sequence of suites.
+        The expression
+            `FwdIter::value_type`
+        must be convertible to `SuiteInfo`.
+        @return `true` if any conditions failed.
+    */
     template <class FwdIter>
     bool
     run(FwdIter first, FwdIter last);
 
-    /**
-     * Conditionally run a sequence of suites.
-     * pred will be called as:
-     * @code
-     *     bool pred(SuiteInfo const&);
-     * @endcode
-     * @return `true` if any conditions failed.
-     */
+    /** Conditionally run a sequence of suites.
+        pred will be called as:
+        @code
+            bool pred(SuiteInfo const&);
+        @endcode
+        @return `true` if any conditions failed.
+    */
     template <class FwdIter, class Pred>
     bool
     runIf(FwdIter first, FwdIter last, Pred pred = Pred{});
 
-    /**
-     * Run all suites in a container.
-     * @return `true` if any conditions failed.
-     */
+    /** Run all suites in a container.
+        @return `true` if any conditions failed.
+    */
     template <class SequenceContainer>
     bool
     runEach(SequenceContainer const& c);
 
-    /**
-     * Conditionally run suites in a container.
-     * pred will be called as:
-     * @code
-     *     bool pred(SuiteInfo const&);
-     * @endcode
-     * @return `true` if any conditions failed.
-     */
+    /** Conditionally run suites in a container.
+        pred will be called as:
+        @code
+            bool pred(SuiteInfo const&);
+        @endcode
+        @return `true` if any conditions failed.
+    */
     template <class SequenceContainer, class Pred>
     bool
     runEachIf(SequenceContainer const& c, Pred pred = Pred{});
 
 protected:
-    /**
-     * Called when a new suite starts.
-     */
+    /// Called when a new suite starts.
     virtual void
     onSuiteBegin(SuiteInfo const&)
     {
     }
 
-    /**
-     * Called when a suite ends.
-     */
+    /// Called when a suite ends.
     virtual void
     onSuiteEnd()
     {
     }
 
-    /**
-     * Called when a new case starts.
-     */
+    /// Called when a new case starts.
     virtual void
     onCaseBegin(std::string const&)
     {
     }
 
-    /**
-     * Called when a new case ends.
-     */
+    /// Called when a new case ends.
     virtual void
     onCaseEnd()
     {
     }
 
-    /**
-     * Called for each passing condition.
-     */
+    /// Called for each passing condition.
     virtual void
     onPass()
     {
     }
 
-    /**
-     * Called for each failing condition.
-     */
+    /// Called for each failing condition.
     virtual void
     onFail(std::string const&)
     {
     }
 
-    /**
-     * Called when a test logs output.
-     */
+    /// Called when a test logs output.
     virtual void
     onLog(std::string const&)
     {

include/xrpl/beast/unit_test/suite.h

@@ -41,14 +41,13 @@ class Thread;
 
 enum class AbortT { NoAbortOnFail, AbortOnFail };
 
-/**
- * A testsuite class.
- *
- * Derived classes execute a series of testcases, where each testcase is
- * a series of pass/fail tests. To provide a unit test using this class,
- * derive from it and use the BEAST_DEFINE_UNIT_TEST macro in a
- * translation unit.
- */
+/** A testsuite class.
+
+    Derived classes execute a series of testcases, where each testcase is
+    a series of pass/fail tests. To provide a unit test using this class,
+    derive from it and use the BEAST_DEFINE_UNIT_TEST macro in a
+    translation unit.
+*/
 class Suite
 {
 private:
@@ -119,17 +118,16 @@ private:
         {
         }
 
-        /**
-         * Open a new testcase.
-         *
-         * A testcase is a series of evaluated test conditions. A test
-         * suite may have multiple test cases. A test is associated with
-         * the last opened testcase. When the test first runs, a default
-         * unnamed case is opened. Tests with only one case may omit the
-         * call to testcase.
-         *
-         * @param abort Determines if suite continues running after a failure.
-         */
+        /** Open a new testcase.
+
+            A testcase is a series of evaluated test conditions. A test
+            suite may have multiple test cases. A test is associated with
+            the last opened testcase. When the test first runs, a default
+            unnamed case is opened. Tests with only one case may omit the
+            call to testcase.
+
+            @param abort Determines if suite continues running after a failure.
+        */
         void
         operator()(std::string const& name, AbortT abort = AbortT::NoAbortOnFail);
 
@@ -142,23 +140,19 @@ private:
     };
 
 public:
-    /**
-     * Logging output stream.
-     *
-     * Text sent to the log output stream will be forwarded to
-     * the output stream associated with the runner.
-     */
+    /** Logging output stream.
+
+        Text sent to the log output stream will be forwarded to
+        the output stream associated with the runner.
+    */
     LogOs<char> log;
 
-    /**
-     * Memberspace for declaring test cases.
-     */
+    /** Memberspace for declaring test cases. */
     TestcaseT testcase;
 
-    /**
-     * Returns the "current" running suite.
-     * If no suite is running, nullptr is returned.
-     */
+    /** Returns the "current" running suite.
+        If no suite is running, nullptr is returned.
+    */
     static Suite*
     thisSuite()
     {
@@ -174,34 +168,30 @@ public:
     Suite&
     operator=(Suite const&) = delete;
 
-    /**
-     * Invokes the test using the specified runner.
-     *
-     * Data members are set up here instead of the constructor as a
-     * convenience to writing the derived class to avoid repetition of
-     * forwarded constructor arguments to the base.
-     * Normally this is called by the framework for you.
-     */
+    /** Invokes the test using the specified runner.
+
+        Data members are set up here instead of the constructor as a
+        convenience to writing the derived class to avoid repetition of
+        forwarded constructor arguments to the base.
+        Normally this is called by the framework for you.
+    */
     template <class = void>
     void
     operator()(Runner& r);
 
-    /**
-     * Record a successful test condition.
-     */
+    /** Record a successful test condition. */
     template <class = void>
     void
     pass();
 
-    /**
-     * Record a failure.
-     *
-     * @param reason Optional text added to the output on a failure.
-     *
-     * @param file The source code file where the test failed.
-     *
-     * @param line The source code line number where the test failed.
-     */
+    /** Record a failure.
+
+        @param reason Optional text added to the output on a failure.
+
+        @param file The source code file where the test failed.
+
+        @param line The source code line number where the test failed.
+    */
     /** @{ */
     template <class String>
     void
@@ -212,24 +202,23 @@ public:
     fail(std::string const& reason = "");
     /** @} */
 
-    /**
-     * Evaluate a test condition.
-     *
-     * This function provides improved logging by incorporating the
-     * file name and line number into the reported output on failure,
-     * as well as additional text specified by the caller.
-     *
-     * @param shouldBeTrue The condition to test. The condition
-     * is evaluated in a boolean context.
-     *
-     * @param reason Optional added text to output on a failure.
-     *
-     * @param file The source code file where the test failed.
-     *
-     * @param line The source code line number where the test failed.
-     *
-     * @return `true` if the test condition indicates success.
-     */
+    /** Evaluate a test condition.
+
+        This function provides improved logging by incorporating the
+        file name and line number into the reported output on failure,
+        as well as additional text specified by the caller.
+
+        @param shouldBeTrue The condition to test. The condition
+        is evaluated in a boolean context.
+
+        @param reason Optional added text to output on a failure.
+
+        @param file The source code file where the test failed.
+
+        @param line The source code line number where the test failed.
+
+        @return `true` if the test condition indicates success.
+    */
     /** @{ */
     template <class Condition>
     bool
@@ -286,19 +275,15 @@ public:
         return unexcept(f, "");
     }
 
-    /**
-     * Return the argument associated with the runner.
-     */
+    /** Return the argument associated with the runner. */
     std::string const&
     arg() const
     {
         return runner_->arg();
     }
 
-    /**
-     * DEPRECATED
-     * @return `true` if the test condition indicates success(a false value)
-     */
+    // DEPRECATED
+    // @return `true` if the test condition indicates success(a false value)
     template <class Condition, class String>
     bool
     unexpected(Condition shouldBeFalse, String const& reason);
@@ -320,9 +305,7 @@ private:
         return &kPTs;
     }
 
-    /**
-     * Runs the suite.
-     */
+    /** Runs the suite. */
     virtual void
     run() = 0;
 
@@ -575,20 +558,18 @@ Suite::run(Runner& r)
 }
 
 #ifndef BEAST_EXPECT
-/**
- * Check a precondition.
- *
- * If the condition is false, the file and line number are reported.
- */
+/** Check a precondition.
+
+    If the condition is false, the file and line number are reported.
+*/
 #define BEAST_EXPECT(cond) expect(cond, __FILE__, __LINE__)
 #endif
 
 #ifndef BEAST_EXPECTS
-/**
- * Check a precondition.
- *
- * If the condition is false, the file and line number are reported.
- */
+/** Check a precondition.
+
+    If the condition is false, the file and line number are reported.
+*/
 #define BEAST_EXPECTS(cond, reason) \
     ((cond) ? (pass(), true) : (fail((reason), __FILE__, __LINE__), false))
 #endif
@@ -612,43 +593,41 @@ Suite::run(Runner& r)
 //
 #ifndef BEAST_DEFINE_TESTSUITE
 
-/**
- * Enables insertion of test suites into the global container.
- * The default is to insert all test suite definitions into the global
- * container. If BEAST_DEFINE_TESTSUITE is user defined, this macro
- * has no effect.
- */
+/** Enables insertion of test suites into the global container.
+    The default is to insert all test suite definitions into the global
+    container. If BEAST_DEFINE_TESTSUITE is user defined, this macro
+    has no effect.
+*/
 #ifndef BEAST_NO_UNIT_TEST_INLINE
 #define BEAST_NO_UNIT_TEST_INLINE 0
 #endif
 
-/**
- * Define a unit test suite.
- *
- * Class     The type representing the class being tested.
- * Module    Identifies the module.
- * Library   Identifies the library.
- *
- * The declaration for the class implementing the test should be the same
- * as Class ## _test. For example, if Class is aged_ordered_container, the
- * test class must be declared as:
- *
- * @code
- *
- * struct aged_ordered_container_test : beast::unit_test::suite
- * {
- *     //...
- * };
- *
- * @endcode
- *
- * The macro invocation must appear in the same namespace as the test class.
- *
- * Unit test priorities were introduced so parallel unit_test::suites would
- * execute faster. Suites with longer running times have higher priorities
- * than unit tests with shorter running times.  Suites with no priorities
- * are assumed to run most quickly, so they run last.
- */
+/** Define a unit test suite.
+
+    Class     The type representing the class being tested.
+    Module    Identifies the module.
+    Library   Identifies the library.
+
+    The declaration for the class implementing the test should be the same
+    as Class ## _test. For example, if Class is aged_ordered_container, the
+    test class must be declared as:
+
+    @code
+
+    struct aged_ordered_container_test : beast::unit_test::suite
+    {
+        //...
+    };
+
+    @endcode
+
+    The macro invocation must appear in the same namespace as the test class.
+
+    Unit test priorities were introduced so parallel unit_test::suites would
+    execute faster. Suites with longer running times have higher priorities
+    than unit tests with shorter running times.  Suites with no priorities
+    are assumed to run most quickly, so they run last.
+*/
 
 #if BEAST_NO_UNIT_TEST_INLINE
 #define BEAST_DEFINE_TESTSUITE(Class, Module, Library)

include/xrpl/beast/unit_test/suite_info.h

@@ -13,9 +13,7 @@ namespace beast::unit_test {
 
 class Runner;
 
-/**
- * Associates a unit test type with metadata.
- */
+/** Associates a unit test type with metadata. */
 class SuiteInfo
 {
     using run_type = std::function<void(Runner&)>;
@@ -62,27 +60,21 @@ public:
         return library_;
     }
 
-    /**
-     * Returns `true` if this suite only runs manually.
-     */
+    /// Returns `true` if this suite only runs manually.
     [[nodiscard]] bool
     manual() const
     {
         return manual_;
     }
 
-    /**
-     * Return the canonical suite name as a string.
-     */
+    /// Return the canonical suite name as a string.
     [[nodiscard]] std::string
     fullName() const
     {
         return library_ + "." + module_ + "." + name_;
     }
 
-    /**
-     * Run a new instance of the associated test suite.
-     */
+    /// Run a new instance of the associated test suite.
     void
     run(Runner& r) const
     {
@@ -101,9 +93,7 @@ public:
 
 //------------------------------------------------------------------------------
 
-/**
- * Convenience for producing SuiteInfo for a given test type.
- */
+/// Convenience for producing SuiteInfo for a given test type.
 template <class Suite>
 SuiteInfo
 makeSuiteInfo(std::string name, std::string module, std::string library, bool manual, int priority)

include/xrpl/beast/unit_test/suite_list.h

@@ -10,15 +10,13 @@
 #include <boost/assert.hpp>
 
 #include <set>
-#include <string>         // IWYU pragma: keep
-#include <typeindex>      // IWYU pragma: keep
-#include <unordered_set>  // IWYU pragma: keep
+#include <string>
+#include <typeindex>
+#include <unordered_set>
 
 namespace beast::unit_test {
 
-/**
- * A container of test suites.
- */
+/// A container of test suites.
 class SuiteList : public detail::ConstContainer<std::set<SuiteInfo>>
 {
 private:
@@ -28,11 +26,10 @@ private:
 #endif
 
 public:
-    /**
-     * Insert a suite into the set.
-     *
-     * The suite must not already exist.
-     */
+    /** Insert a suite into the set.
+
+        The suite must not already exist.
+    */
     template <class Suite>
     void
     insert(char const* name, char const* module, char const* library, bool manual, int priority);

include/xrpl/beast/unit_test/thread.h

@@ -14,9 +14,7 @@
 
 namespace beast::unit_test {
 
-/**
- * Replacement for std::thread that handles exceptions in unit tests.
- */
+/** Replacement for std::thread that handles exceptions in unit tests. */
 class Thread
 {
 private:
@@ -47,10 +45,7 @@ public:
     template <class F, class... Args>
     explicit Thread(Suite& s, F&& f, Args&&... args) : s_(&s)
     {
-        std::function<void(void)> b = [f = std::forward<F>(f),
-                                       ... args = std::forward<Args>(args)]() mutable {
-            std::invoke(f, args...);
-        };
+        std::function<void(void)> b = std::bind(std::forward<F>(f), std::forward<Args>(args)...);
         t_ = std::thread(&Thread::run, this, std::move(b));
     }
 

include/xrpl/beast/utility/Journal.h

@@ -10,9 +10,7 @@
 
 namespace beast {
 
-/**
- * Severity level / threshold of a Journal message.
- */
+/** Severity level / threshold of a Journal message. */
 enum class Severity : std::uint8_t {
     All = 0,
 
@@ -27,19 +25,18 @@ enum class Severity : std::uint8_t {
     None = Disabled
 };
 
-/**
- * A generic endpoint for log messages.
- *
- * The Journal has a few simple goals:
- *
- *  * To be light-weight and copied by value.
- *  * To allow logging statements to be left in source code.
- *  * The logging is controlled at run-time based on a logging threshold.
- *
- * It is advisable to check Journal::active(level) prior to formatting log
- * text.  Doing so sidesteps expensive text formatting when the results
- * will not be sent to the log.
- */
+/** A generic endpoint for log messages.
+
+    The Journal has a few simple goals:
+
+     * To be light-weight and copied by value.
+     * To allow logging statements to be left in source code.
+     * The logging is controlled at run-time based on a logging threshold.
+
+    It is advisable to check Journal::active(level) prior to formatting log
+    text.  Doing so sidesteps expensive text formatting when the results
+    will not be sent to the log.
+*/
 class Journal
 {
 public:
@@ -52,9 +49,7 @@ private:
 public:
     //--------------------------------------------------------------------------
 
-    /**
-     * Abstraction for the underlying message destination.
-     */
+    /** Abstraction for the underlying message destination. */
     class Sink
     {
     protected:
@@ -68,47 +63,36 @@ public:
         Sink&
         operator=(Sink const& lhs) = delete;
 
-        /**
-         * Returns `true` if text at the passed severity produces output.
-         */
+        /** Returns `true` if text at the passed severity produces output. */
         [[nodiscard]] virtual bool
         active(Severity level) const;
 
-        /**
-         * Returns `true` if a message is also written to the Output Window
-         * (MSVC).
-         */
+        /** Returns `true` if a message is also written to the Output Window
+         * (MSVC). */
         [[nodiscard]] virtual bool
         console() const;
 
-        /**
-         * Set whether messages are also written to the Output Window (MSVC).
+        /** Set whether messages are also written to the Output Window (MSVC).
          */
         virtual void
         console(bool output);
 
-        /**
-         * Returns the minimum severity level this sink will report.
-         */
+        /** Returns the minimum severity level this sink will report. */
         [[nodiscard]] virtual Severity
         threshold() const;
 
-        /**
-         * Set the minimum severity this sink will report.
-         */
+        /** Set the minimum severity this sink will report. */
         virtual void
         threshold(Severity thresh);
 
-        /**
-         * Write text to the sink at the specified severity.
-         * A conforming implementation will not write the text if the passed
-         * level is below the current threshold().
-         */
+        /** Write text to the sink at the specified severity.
+            A conforming implementation will not write the text if the passed
+            level is below the current threshold().
+        */
         virtual void
         write(Severity level, std::string const& text) = 0;
 
-        /**
-         * Bypass filter and write text to the sink at the specified severity.
+        /** Bypass filter and write text to the sink at the specified severity.
          * Always write the message, but maintain the same formatting as if
          * it passed through a level filter.
          *
@@ -124,17 +108,15 @@ public:
     };
 
 #ifndef __INTELLISENSE__
-    static_assert(!std::is_default_constructible_v<Sink>);
-    static_assert(!std::is_copy_constructible_v<Sink>);
-    static_assert(!std::is_move_constructible_v<Sink>);
-    static_assert(!std::is_copy_assignable_v<Sink>);
-    static_assert(!std::is_move_assignable_v<Sink>);
-    static_assert(std::is_nothrow_destructible_v<Sink>);
+    static_assert(!std::is_default_constructible_v<Sink>, "");
+    static_assert(!std::is_copy_constructible_v<Sink>, "");
+    static_assert(!std::is_move_constructible_v<Sink>, "");
+    static_assert(!std::is_copy_assignable_v<Sink>, "");
+    static_assert(!std::is_move_assignable_v<Sink>, "");
+    static_assert(std::is_nothrow_destructible_v<Sink>, "");
 #endif
 
-    /**
-     * Returns a Sink which does nothing.
-     */
+    /** Returns a Sink which does nothing. */
     static Sink&
     getNullSink();
 
@@ -182,43 +164,36 @@ public:
     };
 
 #ifndef __INTELLISENSE__
-    static_assert(!std::is_default_constructible_v<ScopedStream>);
-    static_assert(std::is_copy_constructible_v<ScopedStream>);
-    static_assert(std::is_move_constructible_v<ScopedStream>);
-    static_assert(!std::is_copy_assignable_v<ScopedStream>);
-    static_assert(!std::is_move_assignable_v<ScopedStream>);
-    static_assert(std::is_nothrow_destructible_v<ScopedStream>);
+    static_assert(!std::is_default_constructible_v<ScopedStream>, "");
+    static_assert(std::is_copy_constructible_v<ScopedStream>, "");
+    static_assert(std::is_move_constructible_v<ScopedStream>, "");
+    static_assert(!std::is_copy_assignable_v<ScopedStream>, "");
+    static_assert(!std::is_move_assignable_v<ScopedStream>, "");
+    static_assert(std::is_nothrow_destructible_v<ScopedStream>, "");
 #endif
 
     //--------------------------------------------------------------------------
 public:
-    /**
-     * Provide a light-weight way to check active() before string formatting
-     */
+    /** Provide a light-weight way to check active() before string formatting */
     class Stream
     {
     public:
-        /**
-         * Create a stream which produces no output.
-         */
+        /** Create a stream which produces no output. */
         explicit Stream() : sink_(getNullSink()), level_(Severity::Disabled)
         {
         }
 
-        /**
-         * Create a stream that writes at the given level.
-         *
-         * Constructor is inlined so checking active() very inexpensive.
-         */
+        /** Create a stream that writes at the given level.
+
+            Constructor is inlined so checking active() very inexpensive.
+        */
         Stream(Sink& sink, Severity level) : sink_(sink), level_(level)
         {
             XRPL_ASSERT(
                 level_ < Severity::Disabled, "beast::Journal::Stream::Stream : maximum level");
         }
 
-        /**
-         * Construct or copy another Stream.
-         */
+        /** Construct or copy another Stream. */
         Stream(Stream const& other) : Stream(other.sink_, other.level_)
         {
         }
@@ -226,27 +201,21 @@ public:
         Stream&
         operator=(Stream const& other) = delete;
 
-        /**
-         * Returns the Sink that this Stream writes to.
-         */
+        /** Returns the Sink that this Stream writes to. */
         [[nodiscard]] Sink&
         sink() const
         {
             return sink_;
         }
 
-        /**
-         * Returns the Severity level of messages this Stream reports.
-         */
+        /** Returns the Severity level of messages this Stream reports. */
         [[nodiscard]] Severity
         level() const
         {
             return level_;
         }
 
-        /**
-         * Returns `true` if sink logs anything at this stream's level.
-         */
+        /** Returns `true` if sink logs anything at this stream's level. */
         /** @{ */
         [[nodiscard]] bool
         active() const
@@ -261,9 +230,7 @@ public:
         }
         /** @} */
 
-        /**
-         * Output stream support.
-         */
+        /** Output stream support. */
         /** @{ */
         ScopedStream
         operator<<(std::ostream& manip(std::ostream&)) const;
@@ -279,60 +246,49 @@ public:
     };
 
 #ifndef __INTELLISENSE__
-    static_assert(std::is_default_constructible_v<Stream>);
-    static_assert(std::is_copy_constructible_v<Stream>);
-    static_assert(std::is_move_constructible_v<Stream>);
-    static_assert(!std::is_copy_assignable_v<Stream>);
-    static_assert(!std::is_move_assignable_v<Stream>);
-    static_assert(std::is_nothrow_destructible_v<Stream>);
+    static_assert(std::is_default_constructible_v<Stream>, "");
+    static_assert(std::is_copy_constructible_v<Stream>, "");
+    static_assert(std::is_move_constructible_v<Stream>, "");
+    static_assert(!std::is_copy_assignable_v<Stream>, "");
+    static_assert(!std::is_move_assignable_v<Stream>, "");
+    static_assert(std::is_nothrow_destructible_v<Stream>, "");
 #endif
 
     //--------------------------------------------------------------------------
 
-    /**
-     * Journal has no default constructor.
-     */
+    /** Journal has no default constructor. */
     Journal() = delete;
 
-    /**
-     * Create a journal that writes to the specified sink.
-     */
+    /** Create a journal that writes to the specified sink. */
     explicit Journal(Sink& sink) : sink_(&sink)
     {
     }
 
-    /**
-     * Returns the Sink associated with this Journal.
-     */
+    /** Returns the Sink associated with this Journal. */
     [[nodiscard]] Sink&
     sink() const
     {
         return *sink_;
     }
 
-    /**
-     * Returns a stream for this sink, with the specified severity level.
-     */
+    /** Returns a stream for this sink, with the specified severity level. */
     [[nodiscard]] Stream
     stream(Severity level) const
     {
         return Stream(*sink_, level);
     }
 
-    /**
-     * Returns `true` if any message would be logged at this severity level.
-     * For a message to be logged, the severity must be at or above the
-     * sink's severity threshold.
-     */
+    /** Returns `true` if any message would be logged at this severity level.
+        For a message to be logged, the severity must be at or above the
+        sink's severity threshold.
+    */
     [[nodiscard]] bool
     active(Severity level) const
     {
         return sink_->active(level);
     }
 
-    /**
-     * Severity stream access functions.
-     */
+    /** Severity stream access functions. */
     /** @{ */
     [[nodiscard]] Stream
     trace() const
@@ -373,12 +329,12 @@ public:
 };
 
 #ifndef __INTELLISENSE__
-static_assert(!std::is_default_constructible_v<Journal>);
-static_assert(std::is_copy_constructible_v<Journal>);
-static_assert(std::is_move_constructible_v<Journal>);
-static_assert(std::is_copy_assignable_v<Journal>);
-static_assert(std::is_move_assignable_v<Journal>);
-static_assert(std::is_nothrow_destructible_v<Journal>);
+static_assert(!std::is_default_constructible_v<Journal>, "");
+static_assert(std::is_copy_constructible_v<Journal>, "");
+static_assert(std::is_move_constructible_v<Journal>, "");
+static_assert(std::is_copy_assignable_v<Journal>, "");
+static_assert(std::is_move_assignable_v<Journal>, "");
+static_assert(std::is_nothrow_destructible_v<Journal>, "");
 #endif
 
 //------------------------------------------------------------------------------

include/xrpl/beast/utility/PropertyStream.h

@@ -12,9 +12,7 @@ namespace beast {
 
 //------------------------------------------------------------------------------
 
-/**
- * Abstract stream with RAII containers that produce a property tree.
- */
+/** Abstract stream with RAII containers that produce a property tree. */
 class PropertyStream
 {
 public:
@@ -308,9 +306,7 @@ public:
 //
 //------------------------------------------------------------------------------
 
-/**
- * Subclasses can be called to write to a stream and have children.
- */
+/** Subclasses can be called to write to a stream and have children. */
 class PropertyStream::Source
 {
 private:
@@ -328,22 +324,17 @@ public:
     Source&
     operator=(Source const&) = delete;
 
-    /**
-     * Returns the name of this source.
-     */
+    /** Returns the name of this source. */
     [[nodiscard]] std::string const&
     name() const;
 
-    /**
-     * Add a child source.
-     */
+    /** Add a child source. */
     void
     add(Source& source);
 
-    /**
-     * Add a child source by pointer.
-     * The source pointer is returned so it can be used in ctor-initializers.
-     */
+    /** Add a child source by pointer.
+        The source pointer is returned so it can be used in ctor-initializers.
+    */
     template <class Derived>
     Derived*
     add(Derived* child)
@@ -352,55 +343,45 @@ public:
         return child;
     }
 
-    /**
-     * Remove a child source from this Source.
-     */
+    /** Remove a child source from this Source. */
     void
     remove(Source& child);
 
-    /**
-     * Remove all child sources from this Source.
-     */
+    /** Remove all child sources from this Source. */
     void
     removeAll();
 
-    /**
-     * Write only this Source to the stream.
-     */
+    /** Write only this Source to the stream. */
     void
     writeOne(PropertyStream& stream);
 
-    /**
-     * write this source and all its children recursively to the stream.
-     */
+    /** write this source and all its children recursively to the stream. */
     void
     write(PropertyStream& stream);
 
-    /**
-     * Parse the path and write the corresponding Source and optional children.
-     * If the source is found, it is written. If the wildcard character '*'
-     * exists as the last character in the path, then all the children are
-     * written recursively.
-     */
+    /** Parse the path and write the corresponding Source and optional children.
+        If the source is found, it is written. If the wildcard character '*'
+        exists as the last character in the path, then all the children are
+        written recursively.
+    */
     void
     write(PropertyStream& stream, std::string const& path);
 
-    /**
-     * Parse the dot-delimited Source path and return the result.
-     *  The first value will be a pointer to the Source object corresponding
-     *  to the given path. If no Source object exists, then the first value
-     *  will be nullptr and the second value will be undefined.
-     *  The second value is a boolean indicating whether or not the path string
-     *  specifies the wildcard character '*' as the last character.
-     *
-     *  print statement examples
-     *  "parent.child" prints child and all of its children
-     *  "parent.child." start at the parent and print down to child
-     *  "parent.grandchild" prints nothing- grandchild not direct descendent
-     *  "parent.grandchild." starts at the parent and prints down to grandchild
-     *  "parent.grandchild.*" starts at parent, print through grandchild
-     * children
-     */
+    /** Parse the dot-delimited Source path and return the result.
+        The first value will be a pointer to the Source object corresponding
+        to the given path. If no Source object exists, then the first value
+        will be nullptr and the second value will be undefined.
+        The second value is a boolean indicating whether or not the path string
+        specifies the wildcard character '*' as the last character.
+
+        print statement examples
+        "parent.child" prints child and all of its children
+        "parent.child." start at the parent and print down to child
+        "parent.grandchild" prints nothing- grandchild not direct descendent
+        "parent.grandchild." starts at the parent and prints down to grandchild
+        "parent.grandchild.*" starts at parent, print through grandchild
+       children
+    */
     std::pair<Source*, bool>
     find(std::string path);
 
@@ -420,10 +401,9 @@ public:
 
     //--------------------------------------------------------------------------
 
-    /**
-     * Subclass override.
-     * The default version does nothing.
-     */
+    /** Subclass override.
+        The default version does nothing.
+    */
     virtual void
     onWrite(Map&);
 };

include/xrpl/beast/utility/WrappedSink.h

@@ -7,9 +7,7 @@
 
 namespace beast {
 
-/**
- * Wraps a Journal::Sink to prefix its output with a string.
- */
+/** Wraps a Journal::Sink to prefix its output with a string. */
 
 // A WrappedSink both is a Sink and has a Sink:
 //   o It inherits from Sink so it has the correct interface.

include/xrpl/beast/utility/Zero.h

@@ -4,34 +4,33 @@
 
 namespace beast {
 
-/**
- * Zero allows classes to offer efficient comparisons to zero.
- *
- * Zero is a struct to allow classes to efficiently compare with zero without
- * requiring an rvalue construction.
- *
- * It's often the case that we have classes which combine a number and a unit.
- * In such cases, comparisons like t > 0 or t != 0 make sense, but comparisons
- * like t > 1 or t != 1 do not.
- *
- * The class Zero allows such comparisons to be easily made.
- *
- * The comparing class T either needs to have a method called signum() which
- * returns a positive number, 0, or a negative; or there needs to be a signum
- * function which resolves in the namespace which takes an instance of T and
- * returns a positive, zero or negative number.
- */
+/** Zero allows classes to offer efficient comparisons to zero.
+
+    Zero is a struct to allow classes to efficiently compare with zero without
+    requiring an rvalue construction.
+
+    It's often the case that we have classes which combine a number and a unit.
+    In such cases, comparisons like t > 0 or t != 0 make sense, but comparisons
+    like t > 1 or t != 1 do not.
+
+    The class Zero allows such comparisons to be easily made.
+
+    The comparing class T either needs to have a method called signum() which
+    returns a positive number, 0, or a negative; or there needs to be a signum
+    function which resolves in the namespace which takes an instance of T and
+    returns a positive, zero or negative number.
+*/
 
 struct Zero
 {
     explicit Zero() = default;
 };
 
-inline constexpr Zero kZero{};
+namespace {
+constexpr Zero kZero{};
+}  // namespace
 
-/**
- * Default implementation of signum calls the method on the class.
- */
+/** Default implementation of signum calls the method on the class. */
 template <typename T>
 auto
 signum(T const& t)

include/xrpl/beast/utility/maybe_const.h

@@ -4,9 +4,7 @@
 
 namespace beast {
 
-/**
- * Makes T const or non const depending on a bool.
- */
+/** Makes T const or non const depending on a bool. */
 template <bool IsConst, class T>
 struct MaybeConst
 {
@@ -15,9 +13,7 @@ struct MaybeConst
         conditional_t<IsConst, typename std::remove_const<T>::type const, std::remove_const_t<T>>;
 };
 
-/**
- * Alias for omitting `typename`.
- */
+/** Alias for omitting `typename`. */
 template <bool IsConst, class T>
 using maybe_const_t = MaybeConst<IsConst, T>::type;