Beast.Asio:

New classes:

  class async_completion:
    Helper class for implementing asynchronous initiation functions.
    See n3964:
        Library Foundations for Asynchronous Operations, Revision 1
        http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3964.pdf

  class basic_streambuf:
    Meets the requirements of Streambuf.

  class buffered_readstream:
    Buffers a ReadStream with a ConstBufferSequence.

  class consuming_buffers:
    Adapts a BufferSequence which wraps the underlying buffer
    sequence and presents fewer bytes, with the retained bytes
    occurring at the end of the sequence.

  class handler_alloc:
    A C++ Allocator the uses asio handler allocation hooks.

  class static_streambuf:
    An implementation of the Streambuf concept that uses a
    fixed size buffer with size determined at compile-time.

  class streambuf_readstream:
    Buffers a ReadStream with a Streambuf.

New functions:

  append_buffers()
    Returns a new BufferSequence which efficiently concatenates
    two or more buffer sequences together.

  prepare_buffers()
    Shortens a buffer sequence. The bytes excluded are at the
    end of the underlying buffer sequence.

  boost::asio::read_until()
    A copy of boost::asio::read_until overloads, modified to work
    with a beast::asio::basic_streambuf.

Debugging:

  buffers_to_string()

    Convert a ConstBufferSequence to a human readable string
    suitable for diagnostics.

type_check.h:

  Metafunctions for checking asio concepts:
    AsyncReadStream, AsyncWriteStream
    SyncReadStream, SyncWriteStream
    ConstBufferSequence, MutableBufferSequence
    Streambuf
    Handler

Changes:

* All symbols moved up a namespace level.
* streambuf provides all move and copy special members,
  behavior of moved from objects is well-defined.

Fixes:

* Fix basic_streambuf iterator category.

Jamroot

@@ -0,0 +1,68 @@
+#
+# Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+#
+# Distributed under the Boost Software License, Version 1.0. (See accompanying
+# file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+#
+
+import os ;
+import feature ;
+import boost ;
+
+boost.use-project ;
+
+if [ os.name ] = SOLARIS
+{
+  lib socket ;
+  lib nsl ;
+}
+else if [ os.name ] = NT
+{
+  lib ws2_32 ;
+  lib mswsock ;
+}
+else if [ os.name ] = HPUX
+{
+  lib ipv6 ;
+}
+else if [ os.name ] = QNXNTO
+{
+  lib socket ;
+}
+else if [ os.name ] = HAIKU
+{
+  lib network ;
+}
+
+build-project test/asio ;
+
+project beast
+    : requirements
+      <include>.
+      #<use>/boost//headers
+      <library>/boost/system//boost_system
+      <define>BOOST_ALL_NO_LIB=1
+      <threading>multi
+      <link>static
+      <runtime-link>static
+      <os>LINUX:<define>_XOPEN_SOURCE=600
+      <os>LINUX:<define>_GNU_SOURCE=1
+      <os>SOLARIS:<define>_XOPEN_SOURCE=500
+      <os>SOLARIS:<define>__EXTENSIONS__
+      <os>SOLARIS:<library>socket
+      <os>SOLARIS:<library>nsl
+      <os>NT:<define>_WIN32_WINNT=0x0501
+      <os>NT,<toolset>cw:<library>ws2_32
+      <os>NT,<toolset>cw:<library>mswsock
+      <os>NT,<toolset>gcc:<library>ws2_32
+      <os>NT,<toolset>gcc:<library>mswsock
+      <os>NT,<toolset>gcc-cygwin:<define>__USE_W32_SOCKETS
+      <os>HPUX,<toolset>gcc:<define>_XOPEN_SOURCE_EXTENDED
+      <os>HPUX:<library>ipv6
+      <os>QNXNTO:<library>socket
+      <os>HAIKU:<library>network
+    : usage-requirements
+      <include>.
+    :
+      build-dir bin
+    ;

beast/asio.h

@@ -17,29 +17,22 @@
 */
 //==============================================================================
 
-#ifndef BEAST_ASIO_ERROR_H_INCLUDED
-#define BEAST_ASIO_ERROR_H_INCLUDED
+#ifndef BEAST_ASIO_H_INCLUDED
+#define BEAST_ASIO_H_INCLUDED
 
-#include <boost/asio.hpp>
-#include <boost/asio/ssl/error.hpp>
-
-namespace beast {
-namespace asio {
-
-/** Returns `true` if the error code is a SSL "short read." */
-inline
-bool
-is_short_read (boost::system::error_code const& ec)
-{
-    return (ec.category() == boost::asio::error::get_ssl_category())
-        && (ERR_GET_REASON(ec.value()) == SSL_R_SHORT_READ);
-}
-
-/** Returns a human readable message if the error code is SSL related. */
-std::string
-asio_message(boost::system::error_code const& ec);
-
-}
-}
+#include <beast/asio/append_buffers.h>
+#include <beast/asio/async_completion.h>
+#include <beast/asio/basic_streambuf.h>
+#include <beast/asio/bind_handler.h>
+#include <beast/asio/buffers_adapter.h>
+#include <beast/asio/buffers_debug.h>
+#include <beast/asio/consuming_buffers.h>
+#include <beast/asio/handler_alloc.h>
+#include <beast/asio/placeholders.h>
+#include <beast/asio/prepare_buffers.h>
+#include <beast/asio/static_streambuf.h>
+#include <beast/asio/streambuf.h>
+#include <beast/asio/streambuf_readstream.h>
+#include <beast/asio/type_check.h>
 
 #endif

beast/asio/append_buffers.h

@@ -0,0 +1,517 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_APPEND_BUFFERS_H_INLUDED
+#define BEAST_ASIO_APPEND_BUFFERS_H_INLUDED
+
+#include <boost/asio/buffer.hpp>
+#include <cstdint>
+#include <iterator>
+#include <new>
+#include <stdexcept>
+#include <tuple>
+#include <utility>
+
+namespace beast {
+
+namespace detail {
+
+template<class ValueType, class... Bs>
+class append_buffers_helper
+{
+    std::tuple<Bs...> bs_;
+
+public:
+    using value_type = ValueType;
+
+    class const_iterator;
+
+    append_buffers_helper(append_buffers_helper&&) = default;
+    append_buffers_helper(append_buffers_helper const&) = default;
+    append_buffers_helper& operator=(append_buffers_helper&&) = default;
+    append_buffers_helper& operator=(append_buffers_helper const&) = default;
+
+    explicit
+    append_buffers_helper(Bs const&... bs)
+        : bs_(bs...)
+    {
+    }
+
+    const_iterator
+    begin() const;
+
+    const_iterator
+    end() const;
+};
+
+template<class U>
+std::size_t constexpr
+max_sizeof()
+{
+    return sizeof(U);
+}
+
+template<class U0, class U1, class... Us>
+std::size_t constexpr
+max_sizeof()
+{
+    return
+        max_sizeof<U0>() > max_sizeof<U1, Us...>() ?
+        max_sizeof<U0>() : max_sizeof<U1, Us...>();
+}
+
+template<class ValueType, class... Bs>
+class append_buffers_helper<
+    ValueType, Bs...>::const_iterator
+{
+    std::size_t n_;
+    std::tuple<Bs...> const* bs_;
+    std::array<std::uint8_t,
+        max_sizeof<typename Bs::const_iterator...>()> buf_;
+
+    friend class append_buffers_helper<ValueType, Bs...>;
+
+    template<std::size_t I>
+    using C = std::integral_constant<std::size_t, I>;
+
+    template<std::size_t I>
+    using iter_t = typename std::tuple_element_t<
+        I, std::tuple<Bs...>>::const_iterator;
+
+    template<std::size_t I>
+    iter_t<I>&
+    iter()
+    {
+        return *reinterpret_cast<
+            iter_t<I>*>(buf_.data());
+    }
+
+    template<std::size_t I>
+    iter_t<I> const&
+    iter() const
+    {
+        return *reinterpret_cast<
+            iter_t<I> const*>(buf_.data());
+    }
+
+public:
+    using value_type = ValueType;
+    using pointer = value_type const*;
+    using reference = value_type;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category =
+        std::bidirectional_iterator_tag;
+
+    ~const_iterator();
+    const_iterator();
+    const_iterator(const_iterator&& other);
+    const_iterator(const_iterator const& other);
+    const_iterator& operator=(const_iterator&& other);
+    const_iterator& operator=(const_iterator const& other);
+
+    bool
+    operator==(const_iterator const& other) const;
+
+    bool
+    operator!=(const_iterator const& other) const
+    {
+        return !(*this == other);
+    }
+
+    reference
+    operator*() const;
+
+    pointer
+    operator->() const = delete;
+
+    const_iterator&
+    operator++();
+
+    const_iterator
+    operator++(int)
+    {
+        auto temp = *this;
+        ++(*this);
+        return temp;
+    }
+
+    const_iterator&
+    operator--();
+
+    const_iterator
+    operator--(int)
+    {
+        auto temp = *this;
+        --(*this);
+        return temp;
+    }
+
+private:
+    const_iterator(
+        std::tuple<Bs...> const& bs, bool at_end);
+
+    void
+    construct(C<sizeof...(Bs)>)
+    {
+        auto constexpr I = sizeof...(Bs);
+        n_ = I;
+    }
+
+    template<std::size_t I>
+    void
+    construct(C<I>)
+    {
+        if(std::get<I>(*bs_).begin() !=
+            std::get<I>(*bs_).end())
+        {
+            n_ = I;
+            new(buf_.data()) iter_t<I>{
+                std::get<I>(*bs_).begin()};
+            return;
+        }
+        construct(C<I+1>{});
+    }
+
+    void
+    destroy(C<sizeof...(Bs)>)
+    {
+        return;
+    }
+
+    template<std::size_t I>
+    void
+    destroy(C<I>)
+    {
+        if(n_ == I)
+        {
+            using Iter = iter_t<I>;
+            iter<I>().~Iter();
+            return;
+        }
+        destroy(C<I+1>{});
+    }
+
+    void
+    move(C<sizeof...(Bs)>, const_iterator&&)
+    {
+        return;
+    }
+
+    template<std::size_t I>
+    void
+    move(C<I>, const_iterator&& other)
+    {
+        if(n_ == I)
+        {
+            new(buf_.data()) iter_t<I>{
+                std::move(other.iter<I>())};
+            return;
+        }
+        move(C<I+1>{}, std::move(other));
+    }
+
+    void
+    copy(C<sizeof...(Bs)>, const_iterator const&)
+    {
+        return;
+    }
+
+    template<std::size_t I>
+    void
+    copy(C<I>, const_iterator const& other)
+    {
+        if(n_ == I)
+        {
+            new(buf_.data()) iter_t<I>{
+                other.iter<I>()};
+            return;
+        }
+        copy(C<I+1>{}, other);
+    }
+
+    bool
+    equal(C<sizeof...(Bs)>,
+        const_iterator const&) const
+    {
+        return true;
+    }
+
+    template<std::size_t I>
+    bool
+    equal(C<I>, const_iterator const& other) const
+    {
+        if(n_ == I)
+            return iter<I>() == other.iter<I>();
+        return equal(C<I+1>{}, other);
+    }
+
+    [[noreturn]]
+    reference
+    dereference(C<sizeof...(Bs)>) const
+    {
+        throw std::logic_error("invalid iterator");
+    }
+
+    template<std::size_t I>
+    reference
+    dereference(C<I>) const
+    {
+        if(n_ == I)
+            return *iter<I>();
+        return dereference(C<I+1>{});
+    }
+
+    [[noreturn]]
+    void
+    increment(C<sizeof...(Bs)>)
+    {
+        throw std::logic_error("invalid iterator");
+    }
+
+    template<std::size_t I>
+    void
+    increment(C<I>)
+    {
+        if(n_ == I)
+        {
+            if(++iter<I>() !=
+                    std::get<I>(*bs_).end())
+                return;
+            using Iter = iter_t<I>;
+            iter<I>().~Iter();
+            return construct(C<I+1>{});
+        }
+        increment(C<I+1>{});
+    }
+
+    void
+    decrement(C<sizeof...(Bs)>)
+    {
+        auto constexpr I = sizeof...(Bs);
+        if(n_ == I)
+        {
+            --n_;
+            new(buf_.data()) iter_t<I-1>{
+                std::get<I-1>(*bs_).end()};
+        }
+        decrement(C<I-1>{});
+    }
+
+    void
+    decrement(C<0>)
+    {
+        auto constexpr I = 0;
+        if(iter<I>() != std::get<I>(*bs_).begin())
+        {
+            --iter<I>();
+            return;
+        }
+        throw std::logic_error("invalid iterator");
+    }
+
+    template<std::size_t I>
+    void
+    decrement(C<I>)
+    {
+        if(n_ == I)
+        {
+            if(iter<I>() != std::get<I>(*bs_).begin())
+            {
+                --iter<I>();
+                return;
+            }
+            --n_;
+            using Iter = iter_t<I>;
+            iter<I>().~Iter();
+            new(buf_.data()) iter_t<I-1>{
+                std::get<I-1>(*bs_).end()};
+        }
+        decrement(C<I-1>{});
+    }
+};
+
+//------------------------------------------------------------------------------
+
+template<class ValueType, class... Bs>
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::~const_iterator()
+{
+    destroy(C<0>{});
+}
+
+template<class ValueType, class... Bs>
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::const_iterator()
+    : n_(sizeof...(Bs))
+    , bs_(nullptr)
+{
+}
+
+template<class ValueType, class... Bs>
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::const_iterator(
+    std::tuple<Bs...> const& bs, bool at_end)
+    : bs_(&bs)
+{
+    if(at_end)
+        n_ = sizeof...(Bs);
+    else
+        construct(C<0>{});
+}
+
+template<class ValueType, class... Bs>
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::const_iterator(const_iterator&& other)
+    : n_(other.n_)
+    , bs_(other.bs_)
+{
+    move(C<0>{}, std::move(other));
+}
+
+template<class ValueType, class... Bs>
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::const_iterator(const_iterator const& other)
+    : n_(other.n_)
+    , bs_(other.bs_)
+{
+    copy(C<0>{}, other);
+}
+
+template<class ValueType, class... Bs>
+auto
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::operator=(const_iterator&& other) ->
+    const_iterator&
+{
+    if(&other == this)
+        return *this;
+    destroy(C<0>{});
+    n_ = other.n_;
+    bs_ = other.bs_;
+    move(C<0>{}, std::move(other));
+    return *this;
+}
+
+template<class ValueType, class... Bs>
+auto
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::operator=(const_iterator const& other) ->
+const_iterator&
+{
+    if(&other == this)
+        return *this;
+    destroy(C<0>{});
+    n_ = other.n_;
+    bs_ = other.bs_;
+    copy(C<0>{}, other);
+    return *this;
+}
+
+template<class ValueType, class... Bs>
+bool
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::operator==(const_iterator const& other) const
+{
+    if(bs_ != other.bs_)
+        return false;
+    if(n_ != other.n_)
+        return false;
+    return equal(C<0>{}, other);
+}
+
+template<class ValueType, class... Bs>
+auto
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::operator*() const ->
+    reference
+{
+    return dereference(C<0>{});
+}
+
+template<class ValueType, class... Bs>
+auto
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::operator++() ->
+    const_iterator&
+{
+    increment(C<0>{});
+    return *this;
+}
+
+template<class ValueType, class... Bs>
+auto
+append_buffers_helper<ValueType, Bs...>::
+const_iterator::operator--() ->
+    const_iterator&
+{
+    decrement(C<sizeof...(Bs)>{});
+    return *this;
+}
+
+template<class ValueType, class... Bs>
+auto
+append_buffers_helper<ValueType, Bs...>::begin() const ->
+    const_iterator
+{
+    return const_iterator(bs_, false);
+}
+
+template<class ValueType, class... Bs>
+auto
+append_buffers_helper<ValueType, Bs...>::end() const ->
+    const_iterator
+{
+    return const_iterator(bs_, true);
+}
+
+} // detail
+
+//------------------------------------------------------------------------------
+
+/** Concatenate 2 or more buffer sequences to form a `ConstBufferSequence`.
+
+    This function returns a `ConstBufferSequence` that when iterated,
+    efficiently concatenates the input buffer sequences. Copies of the
+    arguments passed will be made; however, the returned object does
+    not take ownership of the underlying memory. The application is still
+    responsible for managing the lifetime of the referenced memory.
+
+    @param buffers The list of buffer sequences to concatenate.
+
+    @return A new `ConstBufferSequence` that represents the concatenation
+    of the input buffer sequences.
+*/
+#if GENERATING_DOCS
+template<class... BufferSequence>
+implementation_defined
+append_buffers(BufferSequence const&... buffers)
+#else
+template<class B1, class B2, class... Bn>
+auto
+append_buffers(B1 const& b1, B2 const& b2, Bn const&... bn)
+#endif
+{
+    return detail::append_buffers_helper<
+        boost::asio::const_buffer,
+            B1, B2, Bn...>(b1, b2, bn...);
+}
+
+} // beast
+
+#endif

beast/asio/async_completion.h

@@ -0,0 +1,96 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_ASYNC_COMPLETION_H_INLUDED
+#define BEAST_ASIO_ASYNC_COMPLETION_H_INLUDED
+
+#include <beast/asio/type_check.h>
+#include <boost/asio/async_result.hpp>
+#include <boost/asio/handler_type.hpp>
+#include <type_traits>
+#include <utility>
+
+namespace beast {
+
+/** Completion helper for implementing the extensible asynchronous model.
+
+    This class template is used to transform caller-provided
+    completion tokens in calls to asynchronous initiation
+    functions. The transformation allows customization of
+    the return type of the initiating function, and the type
+    of the final handler.
+
+    @tparam CompletionToken A CompletionHandler, or a user defined type
+    with specializations for customizing the return type (for example,
+    `boost::asio::use_future` or `boost::asio::yield_context`).
+
+    @tparam Signature The callable signature of the final completion handler.
+
+    Usage:
+    @code
+    template<class CompletionToken>
+    auto
+    async_initfn(..., CompletionToken&& token)
+    {
+        async_completion<CompletionToken,
+            void(error_code, std::size_t)> completion(token);
+        ...
+        return completion.result.get();
+    }
+    @endcode
+
+    See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3896.pdf">
+        Library Foundations For Asynchronous Operations</a>
+*/
+
+template <class CompletionToken, class Signature>
+struct async_completion
+{
+    /** The type of the final handler.
+
+        Objects of this type will be callable with the
+        specified signature.
+    */
+    using handler_type =
+        typename boost::asio::handler_type<
+            CompletionToken, Signature>::type;
+
+    /** Construct the completion helper.
+
+        @param token The completion token. Copies will be made as
+        required. If `CompletionToken` is movable, it may also be moved.
+    */
+    async_completion(std::remove_reference_t<CompletionToken>& token)
+        : handler(std::forward<CompletionToken>(token))
+        , result(handler)
+    {
+        static_assert(is_Handler<handler_type, Signature>::value,
+            "Handler requirements not met");
+    }
+
+    /** The final completion handler, callable with the specified signature. */
+    handler_type handler;
+
+    /** The return value of the asynchronous initiation function. */
+    boost::asio::async_result<handler_type> result;
+};
+
+} // beast
+
+#endif

beast/asio/basic_streambuf.h

@@ -0,0 +1,350 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_BASIC_STREAMBUF_H_INCLUDED
+#define BEAST_ASIO_BASIC_STREAMBUF_H_INCLUDED
+
+#include <beast/empty_base_optimization.h>
+#include <boost/asio/buffer.hpp>
+#include <boost/intrusive/list.hpp>
+#include <iterator>
+#include <limits>
+#include <memory>
+#include <type_traits>
+
+namespace beast {
+
+/** A `Streambuf` that uses multiple buffers internally.
+
+    The implementation uses a sequence of one or more character arrays
+    of varying sizes. Additional character array objects are appended to
+    the sequence to accommodate changes in the size of the character
+    sequence.
+
+    @tparam Allocator The allocator to use for managing memory.
+*/
+template<class Allocator>
+class basic_streambuf
+#if ! GENERATING_DOCS
+    : private empty_base_optimization<
+        typename std::allocator_traits<Allocator>::
+            template rebind_alloc<std::uint8_t>>
+#endif
+{
+public:
+    using allocator_type = typename
+        std::allocator_traits<Allocator>::
+            template rebind_alloc<std::uint8_t>;
+
+private:
+    class element;
+
+    using alloc_traits = std::allocator_traits<allocator_type>;
+    using list_type = typename boost::intrusive::make_list<element,
+        boost::intrusive::constant_time_size<true>>::type;
+    using iterator = typename list_type::iterator;
+    using const_iterator = typename list_type::const_iterator;
+
+    using size_type = typename std::allocator_traits<Allocator>::size_type;
+    using const_buffer = boost::asio::const_buffer;
+    using mutable_buffer = boost::asio::mutable_buffer;
+
+    static_assert(std::is_base_of<std::bidirectional_iterator_tag,
+        typename std::iterator_traits<iterator>::iterator_category>::value,
+            "BidirectionalIterator requirements not met");
+
+    static_assert(std::is_base_of<std::bidirectional_iterator_tag,
+        typename std::iterator_traits<const_iterator>::iterator_category>::value,
+            "BidirectionalIterator requirements not met");
+
+    list_type list_;        // list of allocated buffers
+    iterator out_;          // element that contains out_pos_
+    size_type alloc_size_;  // min amount to allocate
+    size_type in_size_ = 0; // size of the input sequence
+    size_type in_pos_ = 0;  // input offset in list_.front()
+    size_type out_pos_ = 0; // output offset in *out_
+    size_type out_end_ = 0; // output end offset in list_.back()
+
+public:
+    class const_buffers_type;
+
+    class mutable_buffers_type;
+
+    /// Destructor.
+    ~basic_streambuf();
+
+    /** Move constructor.
+
+        The output sequence of this object will be empty.
+
+        After the move, the moved-from object will have an
+        empty input and output sequence, with no internal
+        buffers allocated.
+
+        @param other The stream buffer to move from.
+    */
+    basic_streambuf(basic_streambuf&& other);
+
+    /** Move constructor.
+
+        The output sequence of this object will be empty.
+
+        After the move, the moved-from object will have an
+        empty input and output sequence, with no internal
+        buffers allocated.
+
+        @param other The stream buffer to move from.
+
+        @param alloc The allocator to associate with the
+        stream buffer.
+    */
+    basic_streambuf(basic_streambuf&& other,
+        allocator_type const& alloc);
+
+    /** Move assignment.
+
+        The output sequence of this object will be empty.
+
+        After the move, the moved-from object will have an
+        empty input and output sequence, with no internal
+        buffers allocated.
+
+        @param other The stream buffer to move from.
+    */
+    basic_streambuf&
+    operator=(basic_streambuf&& other);
+
+    /// Copy constructor.
+    basic_streambuf(basic_streambuf const& other);
+
+    /** Copy constructor.
+
+        The output sequence of this object will be empty.
+
+        @param other The stream buffer to copy.
+
+        @param alloc The allocator to associate with the
+        stream buffer.
+    */
+    basic_streambuf(basic_streambuf const& other,
+        allocator_type const& alloc);
+
+    /** Copy assignment.
+
+        The output sequence of this object will be empty.
+
+        @param other The stream buffer to copy.
+    */
+    basic_streambuf& operator=(basic_streambuf const& other);
+
+    /** Copy constructor.
+
+        The output sequence of this object will be empty.
+
+        @param other The stream buffer to copy.
+    */
+    template<class OtherAlloc>
+    basic_streambuf(basic_streambuf<OtherAlloc> const& other);
+
+    /** Copy constructor.
+
+        The output sequence of this object will be empty.
+
+        @param other The stream buffer to copy.
+
+        @param alloc The allocator to associate with the
+        stream buffer.
+    */
+    template<class OtherAlloc>
+    basic_streambuf(basic_streambuf<OtherAlloc> const& other,
+        allocator_type const& alloc);
+
+    /** Copy assignment.
+
+        The output sequence of this object will be empty.
+
+        @param other The stream buffer to copy.
+    */
+    template<class OtherAlloc>
+    basic_streambuf& operator=(basic_streambuf<OtherAlloc> const& other);
+
+    /** Construct a stream buffer.
+
+        @param alloc_size The size of buffer to allocate. This is a soft
+        limit, calls to prepare for buffers exceeding this size will allocate
+        the larger size.
+
+        @param alloc The allocator to use.
+    */
+    explicit
+    basic_streambuf(std::size_t alloc_size = 1024,
+        Allocator const& alloc = allocator_type{});
+
+    /// Get the associated allocator
+    allocator_type
+    get_allocator() const
+    {
+        return this->member();
+    }
+
+    /// Get the maximum size of the basic_streambuf.
+    size_type
+    max_size() const
+    {
+        return std::numeric_limits<std::size_t>::max();
+    }
+
+    /// Get the size of the input sequence.
+    size_type
+    size() const
+    {
+        return in_size_;
+    }
+
+    /// Get a list of buffers that represents the output sequence, with the given size.
+    mutable_buffers_type
+    prepare(size_type n);
+
+    /// Move bytes from the output sequence to the input sequence.
+    void
+    commit(size_type n);
+
+    /// Get a list of buffers that represents the input sequence.
+    const_buffers_type
+    data() const;
+
+    /// Remove bytes from the input sequence.
+    void
+    consume(size_type n);
+
+    /// Clear everything.
+    void
+    clear();
+
+    // Helper for read_until
+    template<class OtherAllocator>
+    friend
+    std::size_t
+    read_size_helper(basic_streambuf<
+        OtherAllocator> const& streambuf, std::size_t max_size);
+
+private:
+    void
+    move_assign(basic_streambuf& other, std::false_type);
+
+    void
+    move_assign(basic_streambuf& other, std::true_type);
+
+    void
+    copy_assign(basic_streambuf const& other, std::false_type);
+
+    void
+    copy_assign(basic_streambuf const& other, std::true_type);
+
+    void
+    delete_list();
+
+    std::size_t
+    prepare_size() const;
+
+    void
+    debug_check() const;
+};
+
+/// The type used to represent the input sequence as a list of buffers.
+template<class Allocator>
+class basic_streambuf<Allocator>::const_buffers_type
+{
+    basic_streambuf const* sb_ = nullptr;
+
+    friend class basic_streambuf;
+
+    explicit
+    const_buffers_type(basic_streambuf const& sb);
+
+public:
+    using value_type = boost::asio::const_buffer;
+
+    class const_iterator;
+
+    const_buffers_type() = default;
+    const_buffers_type(const_buffers_type const&) = default;
+    const_buffers_type& operator=(const_buffers_type const&) = default;
+
+    const_iterator
+    begin() const;
+
+    const_iterator
+    end() const;
+};
+
+/// The type used to represent the output sequence as a list of buffers.
+template<class Allocator>
+class basic_streambuf<Allocator>::mutable_buffers_type
+{
+    basic_streambuf const* sb_;
+
+    friend class basic_streambuf;
+
+    explicit
+    mutable_buffers_type(basic_streambuf const& sb);
+
+public:
+    using value_type = mutable_buffer;
+
+    class const_iterator;
+
+    mutable_buffers_type() = default;
+    mutable_buffers_type(mutable_buffers_type const&) = default;
+    mutable_buffers_type& operator=(mutable_buffers_type const&) = default;
+
+    const_iterator
+    begin() const;
+
+    const_iterator
+    end() const;
+};
+
+/** Format output to a stream buffer.
+
+    @param streambuf The streambuf to write to.
+
+    @param t The object to write.
+
+    @return The stream buffer.
+*/
+template<class Alloc, class T>
+basic_streambuf<Alloc>&
+operator<<(basic_streambuf<Alloc>& buf, T const& t);
+
+/** Convert the entire basic_streambuf to a string.
+
+    @param streambuf The streambuf to convert.
+
+    @return A string representing the contents of the input sequence.
+*/
+template<class Allocator>
+std::string
+to_string(basic_streambuf<Allocator> const& streambuf);
+
+} // beast
+
+#include <beast/asio/impl/basic_streambuf.ipp>
+
+#endif

beast/asio/bind_handler.h

@@ -23,142 +23,151 @@
 #include <boost/asio/detail/handler_alloc_helpers.hpp>
 #include <boost/asio/detail/handler_cont_helpers.hpp>
 #include <boost/asio/detail/handler_invoke_helpers.hpp>
-
 #include <functional>
 #include <type_traits>
 #include <utility>
 
 namespace beast {
-namespace asio {
 
 namespace detail {
 
 /** Nullary handler that calls Handler with bound arguments.
-    The rebound handler provides the same io_service execution
+
+    The bound handler provides the same io_service execution
     guarantees as the original handler.
 */
-template <class DeducedHandler, class... Args>
+template<class Handler, class... Args>
 class bound_handler
 {
 private:
-    using args_type = std::tuple <std::decay_t <Args>...>;
+    using args_type = std::tuple<std::decay_t<Args>...>;
 
-    std::decay_t <DeducedHandler> m_handler;
-    args_type m_args;
+    Handler h_;
+    args_type args_;
 
-    template <class Handler, class Tuple, std::size_t... S>
-    static void invoke (Handler& h, Tuple& args,
+    template<class Tuple, std::size_t... S>
+    static void invoke(Handler& h, Tuple& args,
         std::index_sequence <S...>)
     {
-        h (std::get <S> (args)...);
+        h(std::get<S>(args)...);
     }
 
 public:
     using result_type = void;
 
+    template<class DeducedHandler>
     explicit
-    bound_handler (DeducedHandler&& handler, Args&&... args)
-        : m_handler (std::forward <DeducedHandler> (handler))
-        , m_args (std::forward <Args> (args)...)
+    bound_handler(DeducedHandler&& handler, Args&&... args)
+        : h_(std::forward<DeducedHandler>(handler))
+        , args_(std::forward<Args>(args)...)
     {
     }
 
     void
-    operator() ()
+    operator()()
     {
-        invoke (m_handler, m_args,
-            std::index_sequence_for <Args...> ());
+        invoke(h_, args_,
+            std::index_sequence_for<Args...> ());
     }
 
     void
-    operator() () const
+    operator()() const
     {
-        invoke (m_handler, m_args,
-            std::index_sequence_for <Args...> ());
-    }
-
-    template <class Function>
-    friend
-    void
-    asio_handler_invoke (Function& f, bound_handler* h)
-    {
-        boost_asio_handler_invoke_helpers::
-            invoke (f, h->m_handler);
-    }
-
-    template <class Function>
-    friend
-    void
-    asio_handler_invoke (Function const& f, bound_handler* h)
-    {
-        boost_asio_handler_invoke_helpers::
-            invoke (f, h->m_handler);
+        invoke(h_, args_,
+            std::index_sequence_for<Args...> ());
     }
 
     friend
     void*
-    asio_handler_allocate (std::size_t size, bound_handler* h)
+    asio_handler_allocate(
+        std::size_t size, bound_handler* h)
     {
         return boost_asio_handler_alloc_helpers::
-            allocate (size, h->m_handler);
+            allocate(size, h->h_);
     }
 
     friend
     void
-    asio_handler_deallocate (void* p, std::size_t size, bound_handler* h)
+    asio_handler_deallocate(
+        void* p, std::size_t size, bound_handler* h)
     {
         boost_asio_handler_alloc_helpers::
-            deallocate (p, size, h->m_handler);
+            deallocate(p, size, h->h_);
     }
 
     friend
     bool
-    asio_handler_is_continuation (bound_handler* h)
+    asio_handler_is_continuation(bound_handler* h)
     {
         return boost_asio_handler_cont_helpers::
-            is_continuation (h->m_handler);
+            is_continuation (h->h_);
+    }
+
+    template<class F>
+    friend
+    void
+    asio_handler_invoke(F&& f, bound_handler* h)
+    {
+        boost_asio_handler_invoke_helpers::
+            invoke(f, h->h_);
     }
 };
 
-}
+} // detail
 
 //------------------------------------------------------------------------------
 
-/** Binds parameters to a handler to produce a nullary functor.
-    The returned handler provides the same io_service execution guarantees
-    as the original handler. This is designed to use as a replacement for
-    io_service::wrap, to ensure that the handler will not be invoked
-    immediately by the calling function.
+/** Bind parameters to a completion handler, creating a wrapped handler.
+
+    This function creates a new handler which  invoked with no parameters
+    calls the original handler with the list of bound arguments. The passed
+    handler and arguments are forwarded into the returned handler, which
+    provides the same `io_service` execution guarantees as the original
+    handler.
+
+    Unlike `io_service::wrap`, the returned handler can be used in a
+    subsequent call to `io_service::post` instead of `io_service::dispatch`,
+    to ensure that the handler will not be invoked immediately by the
+    calling function.
+
+    Example:
+    @code
+    template<class AsyncReadStream, ReadHandler>
+    void
+    do_cancel(AsyncReadStream& stream, ReadHandler&& handler)
+    {
+        stream.get_io_service().post(
+            bind_handler(std::forward<ReadHandler>(handler),
+                boost::asio::error::operation_aborted, 0));
+    }
+    @endcode
+
+    @param handler The handler to wrap.
+
+    @param args A list of arguments to bind to the handler. The
+    arguments are forwarded into the returned
+
 */
-template <class DeducedHandler, class... Args>
-detail::bound_handler <DeducedHandler, Args...>
-bind_handler (DeducedHandler&& handler, Args&&... args)
+template<class CompletionHandler, class... Args>
+#if GENERATING_DOCS
+implementation_defined
+#else
+detail::bound_handler<std::decay_t<CompletionHandler>, Args...>
+#endif
+bind_handler(CompletionHandler&& handler, Args&&... args)
 {
-    return detail::bound_handler <DeducedHandler, Args...> (
-        std::forward <DeducedHandler> (handler),
-            std::forward <Args> (args)...);
+    return detail::bound_handler<std::decay_t<
+        CompletionHandler>, Args...>(std::forward<
+            CompletionHandler>(handler),
+                std::forward<Args>(args)...);
 }
 
-}
-}
-
-//------------------------------------------------------------------------------
+} // beast
 
 namespace std {
-
-template <class Handler, class... Args>
-void bind (beast::asio::detail::bound_handler <
+template<class Handler, class... Args>
+void bind(beast::detail::bound_handler<
     Handler, Args...>, ...) = delete;
-
-#if 0
-template <class Handler, class... Args>
-struct is_bind_expression <
-    beast::asio::detail::bound_handler <Handler, Args...>
-> : std::true_type
-{
-};
-#endif
-
-}
+} // std
 
 #endif

beast/asio/buffers_adapter.h

@@ -0,0 +1,648 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_BUFFERS_ADAPTER_H_INLUDED
+#define BEAST_ASIO_BUFFERS_ADAPTER_H_INLUDED
+
+#include <boost/asio/buffer.hpp>
+#include <algorithm>
+#include <array>
+#include <cstring>
+#include <iterator>
+#include <stdexcept>
+#include <type_traits>
+
+namespace beast {
+
+/** Adapts a `MutableBufferSequence` into a `Streambuf`.
+
+    This class wraps a `MutableBufferSequence` to meet the requirements
+    of `Streambuf`. Upon construction the input and output sequences are
+    empty. A copy of the mutable buffer sequence object is stored; however,
+    ownership of the underlying memory is not transferred. The caller is
+    responsible for making sure that referenced memory remains valid
+    for the duration of any operations.
+
+    The size of the mutable buffer sequence determines the maximum
+    number of bytes which may be prepared and committed.
+
+    @tparam Buffers The type of mutable buffer sequence to wrap.
+*/
+template<class Buffers>
+class buffers_adapter
+{
+private:
+    using buffers_type = std::decay_t<Buffers>;
+    using iter_type = typename buffers_type::const_iterator;
+
+    static auto constexpr is_mutable =
+        std::is_constructible<boost::asio::mutable_buffer,
+            typename std::iterator_traits<iter_type>::value_type>::value;
+
+    Buffers bs_;
+    iter_type begin_;
+    iter_type out_;
+    iter_type end_;
+    std::size_t max_size_;
+    std::size_t in_pos_ = 0;    // offset in *begin_
+    std::size_t in_size_ = 0;   // size of input sequence
+    std::size_t out_pos_ = 0;   // offset in *out_
+    std::size_t out_end_ = 0;   // output end offset
+
+    template<class Deduced>
+    buffers_adapter(Deduced&& other,
+        std::size_t nbegin, std::size_t nout,
+            std::size_t nend)
+        : bs_(std::forward<Deduced>(other).bs_)
+        , begin_(std::next(bs_.begin(), nbegin))
+        , out_(std::next(bs_.begin(), nout))
+        , end_(std::next(bs_.begin(), nend))
+        , max_size_(other.max_size_)
+        , in_pos_(other.in_pos_)
+        , in_size_(other.in_size_)
+        , out_pos_(other.out_pos_)
+        , out_end_(other.out_end_)
+    {
+    }
+
+public:
+    class const_buffers_type;
+    class mutable_buffers_type;
+
+    // Move constructor.
+    buffers_adapter(buffers_adapter&& other);
+
+    // Copy constructor.
+    buffers_adapter(buffers_adapter const& other);
+
+    // Move assignment.
+    buffers_adapter& operator=(buffers_adapter&& other);
+
+    // Copy assignment.
+    buffers_adapter& operator=(buffers_adapter const&);
+
+    /** Construct a buffers adapter.
+
+        @param buffers The mutable buffer sequence to wrap. A copy of
+        the object will be made, but ownership of the memory is not
+        transferred.
+    */
+    explicit
+    buffers_adapter(Buffers const& buffers);
+
+    /// Returns the largest size output sequence possible.
+    std::size_t
+    max_size() const
+    {
+        return max_size_;
+    }
+
+    /// Get the size of the input sequence.
+    std::size_t
+    size() const
+    {
+        return in_size_;
+    }
+
+    /** Get a list of buffers that represents the output sequence, with the given size.
+
+        @throws std::length_error if the size would exceed the limit
+        imposed by the underlying mutable buffer sequence.
+    */
+    mutable_buffers_type
+    prepare(std::size_t n);
+
+    /// Move bytes from the output sequence to the input sequence.
+    void
+    commit(std::size_t n);
+
+    /// Get a list of buffers that represents the input sequence.
+    const_buffers_type
+    data() const;
+
+    /// Remove bytes from the input sequence.
+    void
+    consume(std::size_t n);
+};
+
+//------------------------------------------------------------------------------
+
+/// The type used to represent the input sequence as a list of buffers.
+template<class Buffers>
+class buffers_adapter<Buffers>::const_buffers_type
+{
+    buffers_adapter const* ba_;
+
+public:
+    using value_type = boost::asio::const_buffer;
+
+    class const_iterator;
+
+    const_buffers_type() = default;
+    const_buffers_type(
+        const_buffers_type const&) = default;
+    const_buffers_type& operator=(
+        const_buffers_type const&) = default;
+
+    const_iterator
+    begin() const;
+
+    const_iterator
+    end() const;
+
+private:
+    friend class buffers_adapter;
+
+    const_buffers_type(buffers_adapter const& ba)
+        : ba_(&ba)
+    {
+    }
+};
+
+template<class Buffers>
+class buffers_adapter<Buffers>::const_buffers_type::const_iterator
+{
+    iter_type it_;
+    buffers_adapter const* ba_;
+
+public:
+    using value_type = boost::asio::const_buffer;
+    using pointer = value_type const*;
+    using reference = value_type;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category =
+        std::bidirectional_iterator_tag;
+
+    const_iterator() = default;
+    const_iterator(const_iterator&& other) = default;
+    const_iterator(const_iterator const& other) = default;
+    const_iterator& operator=(const_iterator&& other) = default;
+    const_iterator& operator=(const_iterator const& other) = default;
+
+    bool
+    operator==(const_iterator const& other) const
+    {
+        return ba_ == other.ba_ &&
+            it_ == other.it_;
+    }
+
+    bool
+    operator!=(const_iterator const& other) const
+    {
+        return !(*this == other);
+    }
+
+    reference
+    operator*() const
+    {
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        return value_type{buffer_cast<void const*>(*it_),
+            (ba_->out_ == ba_->bs_.end() ||
+                it_ != ba_->out_) ? buffer_size(*it_) : ba_->out_pos_} +
+                    (it_ == ba_->begin_ ? ba_->in_pos_ : 0);
+    }
+
+    pointer
+    operator->() const = delete;
+
+    const_iterator&
+    operator++()
+    {
+        ++it_;
+        return *this;
+    }
+
+    const_iterator
+    operator++(int)
+    {
+        auto temp = *this;
+        ++(*this);
+        return temp;
+    }
+
+    const_iterator&
+    operator--()
+    {
+        --it_;
+        return *this;
+    }
+
+    const_iterator
+    operator--(int)
+    {
+        auto temp = *this;
+        --(*this);
+        return temp;
+    }
+
+private:
+    friend class const_buffers_type;
+
+    const_iterator(buffers_adapter const& ba,
+            iter_type iter)
+        : it_(iter)
+        , ba_(&ba)
+    {
+    }
+};
+
+template<class Buffers>
+inline
+auto
+buffers_adapter<Buffers>::const_buffers_type::begin() const ->
+    const_iterator
+{
+    return const_iterator{*ba_, ba_->begin_};
+}
+
+template<class Buffers>
+inline
+auto
+buffers_adapter<Buffers>::const_buffers_type::end() const ->
+    const_iterator
+{
+    return const_iterator{*ba_, ba_->out_ ==
+        ba_->end_ ? ba_->end_ : std::next(ba_->out_)};
+}
+
+//------------------------------------------------------------------------------
+
+/// The type used to represent the output sequence as a list of buffers.
+template<class Buffers>
+class buffers_adapter<Buffers>::mutable_buffers_type
+{
+    buffers_adapter const* ba_;
+
+public:
+    using value_type = boost::asio::mutable_buffer;
+
+    class const_iterator;
+
+    mutable_buffers_type() = default;
+    mutable_buffers_type(
+        mutable_buffers_type const&) = default;
+    mutable_buffers_type& operator=(
+        mutable_buffers_type const&) = default;
+
+    const_iterator
+    begin() const;
+
+    const_iterator
+    end() const;
+
+private:
+    friend class buffers_adapter;
+
+    mutable_buffers_type(
+            buffers_adapter const& ba)
+        : ba_(&ba)
+    {
+    }
+};
+
+template<class Buffers>
+class buffers_adapter<Buffers>::mutable_buffers_type::const_iterator
+{
+    iter_type it_;
+    buffers_adapter const* ba_;
+
+public:
+    using value_type = boost::asio::mutable_buffer;
+    using pointer = value_type const*;
+    using reference = value_type;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category =
+        std::bidirectional_iterator_tag;
+
+    const_iterator() = default;
+    const_iterator(const_iterator&& other) = default;
+    const_iterator(const_iterator const& other) = default;
+    const_iterator& operator=(const_iterator&& other) = default;
+    const_iterator& operator=(const_iterator const& other) = default;
+
+    bool
+    operator==(const_iterator const& other) const
+    {
+        return ba_ == other.ba_ &&
+            it_ == other.it_;
+    }
+
+    bool
+    operator!=(const_iterator const& other) const
+    {
+        return !(*this == other);
+    }
+
+    reference
+    operator*() const
+    {
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        return value_type{buffer_cast<void*>(*it_),
+            it_ == std::prev(ba_->end_) ?
+                ba_->out_end_ : buffer_size(*it_)} +
+                    (it_ == ba_->out_ ? ba_->out_pos_ : 0);
+    }
+
+    pointer
+    operator->() const = delete;
+
+    const_iterator&
+    operator++()
+    {
+        ++it_;
+        return *this;
+    }
+
+    const_iterator
+    operator++(int)
+    {
+        auto temp = *this;
+        ++(*this);
+        return temp;
+    }
+
+    const_iterator&
+    operator--()
+    {
+        --it_;
+        return *this;
+    }
+
+    const_iterator
+    operator--(int)
+    {
+        auto temp = *this;
+        --(*this);
+        return temp;
+    }
+
+private:
+    friend class mutable_buffers_type;
+
+    const_iterator(buffers_adapter const& ba,
+            iter_type iter)
+        : it_(iter)
+        , ba_(&ba)
+    {
+    }
+};
+
+template<class Buffers>
+inline
+auto
+buffers_adapter<Buffers>::mutable_buffers_type::begin() const ->
+    const_iterator
+{
+    return const_iterator{*ba_, ba_->out_};
+}
+
+template<class Buffers>
+inline
+auto
+buffers_adapter<Buffers>::mutable_buffers_type::end() const ->
+    const_iterator
+{
+    return const_iterator{*ba_, ba_->end_};
+}
+
+//------------------------------------------------------------------------------
+
+template<class Buffers>
+buffers_adapter<Buffers>::buffers_adapter(
+        buffers_adapter&& other)
+    : buffers_adapter(std::move(other),
+        std::distance<iter_type>(other.bs_.begin(), other.begin_),
+        std::distance<iter_type>(other.bs_.begin(), other.out_),
+        std::distance<iter_type>(other.bs_.begin(), other.end_))
+{
+}
+
+template<class Buffers>
+buffers_adapter<Buffers>::buffers_adapter(
+        buffers_adapter const& other)
+    : buffers_adapter(other,
+        std::distance<iter_type>(other.bs_.begin(), other.begin_),
+        std::distance<iter_type>(other.bs_.begin(), other.out_),
+        std::distance<iter_type>(other.bs_.begin(), other.end_))
+{
+}
+
+template<class Buffers>
+auto
+buffers_adapter<Buffers>::operator=(
+    buffers_adapter&& other) -> buffers_adapter&
+{
+    auto const nbegin = std::distance<iter_type>(
+        other.bs_.begin(), other.begin_);
+    auto const nout = std::distance<iter_type>(
+        other.bs_.begin(), other.out_);
+    auto const nend = std::distance<iter_type>(
+        other.bs_.begin(), other.end_);
+    bs_ = std::move(other.bs_);
+    begin_ = std::next(bs_.begin(), nbegin);
+    out_ = std::next(bs_.begin(), nout);
+    end_ = std::next(bs_.begin(), nend);
+    max_size_ = other.max_size_;
+    in_pos_ = other.in_pos_;
+    in_size_ = other.in_size_;
+    out_pos_ = other.out_pos_;
+    out_end_ = other.out_end_;
+    return *this;
+}
+
+template<class Buffers>
+auto
+buffers_adapter<Buffers>::operator=(
+    buffers_adapter const& other) -> buffers_adapter&
+{
+    auto const nbegin = std::distance<iter_type>(
+        other.bs_.begin(), other.begin_);
+    auto const nout = std::distance<iter_type>(
+        other.bs_.begin(), other.out_);
+    auto const nend = std::distance<iter_type>(
+        other.bs_.begin(), other.end_);
+    bs_ = other.bs_;
+    begin_ = std::next(bs_.begin(), nbegin);
+    out_ = std::next(bs_.begin(), nout);
+    end_ = std::next(bs_.begin(), nend);
+    max_size_ = other.max_size_;
+    in_pos_ = other.in_pos_;
+    in_size_ = other.in_size_;
+    out_pos_ = other.out_pos_;
+    out_end_ = other.out_end_;
+    return *this;
+}
+
+template<class Buffers>
+buffers_adapter<Buffers>::buffers_adapter(
+    Buffers const& bs)
+    : bs_(bs)
+    , begin_(bs_.begin())
+    , out_(bs_.begin())
+    , end_(bs_.begin())
+    , max_size_(boost::asio::buffer_size(bs_))
+{
+}
+
+template<class Buffers>
+auto
+buffers_adapter<Buffers>::prepare(std::size_t n) ->
+    mutable_buffers_type
+{
+    using boost::asio::buffer_size;
+    static_assert(is_mutable,
+        "Operation not valid for ConstBufferSequence");
+    end_ = out_;
+    if(end_ != bs_.end())
+    {
+        auto size = buffer_size(*end_) - out_pos_;
+        if(n > size)
+        {
+            n -= size;
+            while(++end_ != bs_.end())
+            {
+                size = buffer_size(*end_);
+                if(n < size)
+                {
+                    out_end_ = n;
+                    n = 0;
+                    ++end_;
+                    break;
+                }
+                n -= size;
+                out_end_ = size;
+            }
+        }
+        else
+        {
+            ++end_;
+            out_end_ = out_pos_ + n;
+            n = 0;
+        }
+    }
+    if(n > 0)
+        throw std::length_error(
+            "no space in buffers_adapter");
+    return mutable_buffers_type{*this};
+}
+
+template<class Buffers>
+void
+buffers_adapter<Buffers>::commit(std::size_t n)
+{
+    using boost::asio::buffer_size;
+    static_assert(is_mutable,
+        "Operation not valid for ConstBufferSequence");
+    if(out_ == end_)
+        return;
+    auto const last = std::prev(end_);
+    while(out_ != last)
+    {
+        auto const avail =
+            buffer_size(*out_) - out_pos_;
+        if(n < avail)
+        {
+            out_pos_ += n;
+            in_size_ += n;
+            max_size_ -= n;
+            return;
+        }
+        ++out_;
+        n -= avail;
+        out_pos_ = 0;
+        in_size_ += avail;
+        max_size_ -= avail;
+    }
+
+    n = std::min(n, out_end_ - out_pos_);
+    out_pos_ += n;
+    in_size_ += n;
+    max_size_ -= n;
+    if(out_pos_ == buffer_size(*out_))
+    {
+        ++out_;
+        out_pos_ = 0;
+        out_end_ = 0;
+    }
+}
+
+template<class Buffers>
+inline
+auto
+buffers_adapter<Buffers>::data() const ->
+    const_buffers_type
+{
+    return const_buffers_type{*this};
+}
+
+template<class Buffers>
+void
+buffers_adapter<Buffers>::consume(std::size_t n)
+{
+    for(;;)
+    {
+        if(begin_ != out_)
+        {
+            auto const avail =
+                buffer_size(*begin_) - in_pos_;
+            if(n < avail)
+            {
+                in_size_ -= n;
+                in_pos_ += n;
+                break;
+            }
+            n -= avail;
+            in_size_ -= avail;
+            in_pos_ = 0;
+            ++begin_;
+        }
+        else
+        {
+            auto const avail = out_pos_ - in_pos_;
+            if(n < avail)
+            {
+                in_size_ -= n;
+                in_pos_ += n;
+            }
+            else
+            {
+                in_size_ -= avail;
+                if(out_pos_ != out_end_||
+                    out_ != std::prev(bs_.end()))
+                {
+                    in_pos_ = out_pos_;
+                }
+                else
+                {
+                    // Use the whole buffer now.
+                    in_pos_ = 0;
+                    out_pos_ = 0;
+                    out_end_ = 0;
+                }
+            }
+            break;
+        }
+    }
+}
+
+} // beast
+
+#endif

beast/asio/buffers_debug.h

@@ -0,0 +1,52 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_BUFFERS_DEBUG_H_INLUDED
+#define BEAST_ASIO_BUFFERS_DEBUG_H_INLUDED
+
+#include <boost/asio/buffer.hpp>
+#include <string>
+
+namespace beast {
+namespace debug {
+
+template<class Buffers>
+static
+std::string
+buffers_to_string(Buffers const& bs)
+{
+    using boost::asio::buffer_cast;
+    using boost::asio::buffer_size;
+    std::string s;
+    s.reserve(buffer_size(bs));
+    for(auto const& b : bs)
+        s.append(buffer_cast<char const*>(b),
+            buffer_size(b));
+    for(auto i = s.size(); i-- > 0;)
+        if(s[i] == '\r')
+            s.replace(i, 1, "\\r");
+        else if(s[i] == '\n')
+            s.replace(i, 1, "\\n\n");
+    return s;
+}
+
+} // debug
+} // beast
+
+#endif

beast/asio/consuming_buffers.h

@@ -0,0 +1,309 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_CONSUMING_BUFFERS_H_INLUDED
+#define BEAST_ASIO_CONSUMING_BUFFERS_H_INLUDED
+
+#include <beast/asio/type_check.h>
+#include <boost/asio/buffer.hpp>
+#include <cstdint>
+#include <iterator>
+#include <type_traits>
+#include <utility>
+
+namespace beast {
+
+/** Adapter to trim the front of a `BufferSequence`.
+
+    This adapter wraps a buffer sequence to create a new sequence
+    which may be incrementally consumed. Bytes consumed are removed
+    from the front of the buffer. The underlying memory is not changed,
+    instead the adapter efficiently iterates through a subset of
+    the buffers wrapped.
+
+    The wrapped buffer is not modified, a copy is made instead.
+    Ownership of the underlying memory is not transferred, the application
+    is still responsible for managing its lifetime.
+
+    @tparam Buffers The buffer sequence to wrap.
+
+    @ptaram ValueType The type of buffer of the final buffer sequence. This
+    can be different from the buffer type of the wrapped sequence. For
+    example, a `MutableBufferSequence` can be transformed into a
+    consumable `ConstBufferSequence`. Violations of buffer const safety
+    are not permitted, and will result in a compile error.
+*/
+template<class Buffers,
+    class ValueType = typename Buffers::value_type>
+class consuming_buffers
+{
+    using iter_type =
+        typename Buffers::const_iterator;
+
+    static_assert(std::is_constructible<ValueType,
+        typename std::iterator_traits<iter_type>::value_type>::value,
+            "ValueType requirements not met");
+
+    Buffers bs_;
+    iter_type begin_;
+    std::size_t skip_ = 0;
+
+    template<class Deduced>
+    consuming_buffers(Deduced&& other, std::size_t nbegin)
+        : bs_(std::forward<Deduced>(other).bs_)
+        , begin_(std::next(bs_.begin(), nbegin))
+        , skip_(other.skip_)
+    {
+    }
+
+public:
+    /// The type for each element in the list of buffers.
+    using value_type = ValueType;
+
+    class const_iterator;
+
+    /// Move constructor.
+    consuming_buffers(consuming_buffers&&);
+
+    /// Copy constructor.
+    consuming_buffers(consuming_buffers const&);
+
+    /// Move assignment.
+    consuming_buffers& operator=(consuming_buffers&&);
+
+    /// Copy assignment.
+    consuming_buffers& operator=(consuming_buffers const&);
+
+    /** Construct to represent a buffer sequence.
+
+        A copy of the buffer sequence is made. Ownership of the
+        underlying memory is not transferred or copied.
+    */
+    explicit
+    consuming_buffers(Buffers const& buffers);
+
+    /// Get a bidirectional iterator to the first element.
+    const_iterator
+    begin() const;
+
+    /// Get a bidirectional iterator for one past the last element.
+    const_iterator
+    end() const;
+
+    /** Remove bytes from the beginning of the sequence.
+
+        @param n The number of bytes to remove. If this is
+        larger than the number of bytes remaining, all the
+        bytes remaining are removed.
+    */
+    void
+    consume(std::size_t n);
+};
+
+/// A bidirectional iterator type that may be used to read elements.
+template<class Buffers, class ValueType>
+class consuming_buffers<Buffers, ValueType>::const_iterator
+{
+    friend class consuming_buffers<Buffers, ValueType>;
+
+    using iter_type =
+        typename Buffers::const_iterator;
+
+    iter_type it_;
+    consuming_buffers const* b_;
+
+public:
+    using value_type =
+        typename std::iterator_traits<iter_type>::value_type;
+    using pointer = value_type const*;
+    using reference = value_type;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category =
+        std::bidirectional_iterator_tag;
+
+    const_iterator() = default;
+    const_iterator(const_iterator&& other) = default;
+    const_iterator(const_iterator const& other) = default;
+    const_iterator& operator=(const_iterator&& other) = default;
+    const_iterator& operator=(const_iterator const& other) = default;
+
+    bool
+    operator==(const_iterator const& other) const
+    {
+        return b_ == other.b_ && it_ == other.it_;
+    }
+
+    bool
+    operator!=(const_iterator const& other) const
+    {
+        return !(*this == other);
+    }
+
+    reference
+    operator*() const
+    {
+        if(it_ == b_->begin_)
+            return *it_ + b_->skip_;
+        return *it_;
+    }
+
+    pointer
+    operator->() const = delete;
+
+    const_iterator&
+    operator++()
+    {
+        ++it_;
+        return *this;
+    }
+
+    const_iterator
+    operator++(int)
+    {
+        auto temp = *this;
+        ++(*this);
+        return temp;
+    }
+
+    const_iterator&
+    operator--()
+    {
+        --it_;
+        return *this;
+    }
+
+    const_iterator
+    operator--(int)
+    {
+        auto temp = *this;
+        --(*this);
+        return temp;
+    }
+
+private:
+    const_iterator(consuming_buffers const& b,
+            iter_type it)
+        : it_(it)
+        , b_(&b)
+    {
+    }
+};
+
+template<class Buffers, class ValueType>
+consuming_buffers<Buffers, ValueType>::
+consuming_buffers(consuming_buffers&& other)
+    : consuming_buffers(std::move(other),
+        std::distance<iter_type>(
+            other.bs_.begin(), other.begin_))
+{
+}
+
+template<class Buffers, class ValueType>
+consuming_buffers<Buffers, ValueType>::
+consuming_buffers(consuming_buffers const& other)
+    : consuming_buffers(other,
+        std::distance<iter_type>(
+            other.bs_.begin(), other.begin_))
+{
+}
+
+template<class Buffers, class ValueType>
+auto
+consuming_buffers<Buffers, ValueType>::
+operator=(consuming_buffers&& other) ->
+    consuming_buffers&
+{
+    auto const nbegin = std::distance<iter_type>(
+        other.bs_.begin(), other.begin_);
+    bs_ = std::move(other.bs_);
+    begin_ = std::next(bs_.begin(), nbegin);
+    skip_ = other.skip_;
+    return *this;
+}
+
+template<class Buffers, class ValueType>
+auto
+consuming_buffers<Buffers, ValueType>::
+operator=(consuming_buffers const& other) ->
+    consuming_buffers&
+{
+    auto const nbegin = std::distance<iter_type>(
+        other.bs_.begin(), other.begin_);
+    bs_ = other.bs_;
+    begin_ = std::next(bs_.begin(), nbegin);
+    skip_ = other.skip_;
+    return *this;
+}
+
+template<class Buffers, class ValueType>
+consuming_buffers<Buffers, ValueType>::
+consuming_buffers(Buffers const& bs)
+    : bs_(bs)
+    , begin_(bs_.begin())
+{
+}
+
+template<class Buffers, class ValueType>
+auto
+consuming_buffers<Buffers, ValueType>::begin() const ->
+    const_iterator
+{
+    return const_iterator{*this, begin_};
+}
+
+template<class Buffers, class ValueType>
+auto
+consuming_buffers<Buffers, ValueType>::end() const ->
+    const_iterator
+{
+    return const_iterator{*this, bs_.end()};
+}
+
+template<class Buffers, class ValueType>
+void
+consuming_buffers<Buffers, ValueType>::consume(std::size_t n)
+{
+    using boost::asio::buffer_size;
+    for(;n > 0 && begin_ != bs_.end(); ++begin_)
+    {
+        auto const len =
+            buffer_size(*begin_) - skip_;
+        if(n < len)
+        {
+            skip_ += n;
+            break;
+        }
+        n -= len;
+        skip_ = 0;
+    }
+}
+
+/// Returns a consumed buffer
+template<class Buffers>
+consuming_buffers<Buffers, typename Buffers::value_type>
+consumed_buffers(Buffers const& bs, std::size_t n)
+{
+    consuming_buffers<Buffers> cb(bs);
+    cb.consume(n);
+    return cb;
+}
+
+} // beast
+
+#endif

beast/asio/handler_alloc.h

@@ -0,0 +1,150 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_HANDLER_ALLOC_H_INCLUDED
+#define BEAST_ASIO_HANDLER_ALLOC_H_INCLUDED
+
+#include <boost/asio/detail/handler_alloc_helpers.hpp>
+#include <cstdlib>
+#include <memory>
+#include <type_traits>
+#include <utility>
+
+namespace beast {
+
+// Guidance from
+// http://howardhinnant.github.io/allocator_boilerplate.html
+
+/** An allocator that uses handler customizations.
+
+    This allocator uses the handler customizations `asio_handler_allocate`
+    and `asio_handler_deallocate` to manage memory.
+
+    @tparam T The type of object
+
+    @tparam Handler The type of handler.
+*/
+template <class T, class Handler>
+class handler_alloc
+{
+private:
+    // We want a partial template specialization as a friend
+    // but that isn't allowed so we friend all versions. This
+    // should produce a compile error if Handler is not
+    // constructible from H.
+    //
+    template <class U, class H>
+    friend class handler_alloc;
+
+    Handler h_;
+
+public:
+    using value_type = T;
+    using is_always_equal = std::true_type;
+
+    handler_alloc() = delete;
+    handler_alloc(handler_alloc&&) = default;
+    handler_alloc(handler_alloc const&) = default;
+    handler_alloc& operator=(handler_alloc&&) = default;
+    handler_alloc& operator=(handler_alloc const&) = default;
+
+    /** Construct the allocator.
+
+        The handler is moved or copied into the allocator.
+    */
+    explicit
+    handler_alloc(Handler&& h)
+        : h_(std::move(h))
+    {
+    }
+
+    /** Construct the allocator.
+
+        A copy of the handler is made.
+    */
+    explicit
+    handler_alloc(Handler const& h)
+        : h_(h)
+    {
+    }
+
+    template<class U>
+    handler_alloc(
+            handler_alloc<U, Handler>&& other)
+        : h_(std::move(other.h_))
+    {
+    }
+
+    template<class U>
+    handler_alloc(
+            handler_alloc<U, Handler> const& other)
+        : h_(other.h_)
+    {
+    }
+
+    value_type*
+    allocate(std::ptrdiff_t n)
+    {
+        auto const size = n * sizeof(T);
+        return static_cast<value_type*>(
+            boost_asio_handler_alloc_helpers::allocate(
+                size, h_));
+    }
+
+    void
+    deallocate(value_type* p, std::ptrdiff_t n)
+    {
+        auto const size = n * sizeof(T);
+        boost_asio_handler_alloc_helpers::deallocate(
+            p, size, h_);
+    }
+
+#ifdef _MSC_VER
+    // Work-around for MSVC not using allocator_traits
+    // in the implementation of shared_ptr
+    //
+    void
+    destroy(T* t)
+    {
+        t->~T();
+    }
+#endif
+
+    template<class U>
+    friend
+    bool
+    operator==(handler_alloc const& lhs,
+        handler_alloc<U, Handler> const& rhs)
+    {
+        return true;
+    }
+
+    template<class U>
+    friend
+    bool
+    operator!=(handler_alloc const& lhs,
+        handler_alloc<U, Handler> const& rhs)
+    {
+        return !(lhs == rhs);
+    }
+};
+
+} // beast
+
+#endif

beast/asio/impl/basic_streambuf.ipp

@@ -0,0 +1,847 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_BASIC_STREAMBUF_IPP_INCLUDED
+#define BEAST_ASIO_BASIC_STREAMBUF_IPP_INCLUDED
+
+#include <algorithm>
+#include <cassert>
+#include <exception>
+#include <sstream>
+#include <string>
+#include <utility>
+
+namespace beast {
+
+/*  These diagrams illustrate the layout and state variables.
+
+    Input and output contained entirely in one element:
+
+    0                            out_
+    |<-------------+------------------------------------------->|
+    in_pos_       out_pos_                                     out_end_
+
+
+    Output contained in first and second elements:
+
+                    out_
+    |<------+----------+------->|   |<----------+-------------->|
+            in_pos_   out_pos_                 out_end_
+
+
+    Output contained in the second element:
+
+                                                    out_
+    |<------------+------------>|   |<----+-------------------->|
+                in_pos_                out_pos_              out_end_
+
+
+    Output contained in second and third elements:
+
+                                    out_
+    |<-----+-------->|   |<-------+------>|   |<--------------->|
+            in_pos_               out_pos_                      out_end_
+
+
+    Input sequence is empty:
+
+                    out_
+    |<------+------------------>|   |<-----------+------------->|
+            out_pos_                             out_end_
+            in_pos_
+
+
+    Output sequence is empty:
+
+                                                    out_
+    |<------+------------------>|   |<------+------------------>|
+            in_pos_                        out_pos_
+                                            out_end_
+
+
+    The end of output can point to the end of an element.
+    But out_pos_ should never point to the end:
+
+                                                    out_
+    |<------+------------------>|   |<------+------------------>|
+            in_pos_                        out_pos_            out_end_
+
+
+    When the input sequence entirely fills the last element and
+    the output sequence is empty, out_ will point to the end of
+    the list of buffers, and out_pos_ and out_end_ will be 0:
+
+
+    |<------+------------------>|   out_     == list_.end()
+            in_pos_                   out_pos_ == 0
+                                    out_end_ == 0
+*/
+
+template<class Allocator>
+class basic_streambuf<Allocator>::element
+    : public boost::intrusive::list_base_hook<
+        boost::intrusive::link_mode<
+            boost::intrusive::normal_link>>
+{
+    using size_type = typename std::allocator_traits<Allocator>::size_type;
+
+    size_type const size_;
+
+public:
+    element(element const&) = delete;
+    element& operator=(element const&) = delete;
+
+    explicit
+    element(size_type n)
+        : size_(n)
+    {
+    }
+
+    size_type
+    size() const
+    {
+        return size_;
+    }
+
+    char*
+    data() const
+    {
+        return const_cast<char*>(
+            reinterpret_cast<char const*>(this+1));
+    }
+};
+
+//------------------------------------------------------------------------------
+
+template<class Allocator>
+class basic_streambuf<Allocator>::const_buffers_type::const_iterator
+{
+    basic_streambuf const* sb_ = nullptr;
+    typename list_type::const_iterator it_;
+
+public:
+    using value_type =
+        typename const_buffers_type::value_type;
+    using pointer = value_type const*;
+    using reference = value_type;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category =
+        std::bidirectional_iterator_tag;
+
+    const_iterator() = default;
+    const_iterator(const_iterator&& other) = default;
+    const_iterator(const_iterator const& other) = default;
+    const_iterator& operator=(const_iterator&& other) = default;
+    const_iterator& operator=(const_iterator const& other) = default;
+
+    const_iterator(basic_streambuf const& sb,
+            typename list_type::const_iterator const& it)
+        : sb_(&sb)
+        , it_(it)
+    {
+    }
+
+    bool
+    operator==(const_iterator const& other) const
+    {
+        return sb_ == other.sb_ && it_ == other.it_;
+    }
+
+    bool
+    operator!=(const_iterator const& other) const
+    {
+        return !(*this == other);
+    }
+
+    reference
+    operator*() const
+    {
+        auto const& e = *it_;
+        return value_type{e.data(),
+           (sb_->out_ == sb_->list_.end() ||
+                &e != &*sb_->out_) ? e.size() : sb_->out_pos_} +
+                   (&e == &*sb_->list_.begin() ? sb_->in_pos_ : 0);
+    }
+
+    pointer
+    operator->() const = delete;
+
+    const_iterator&
+    operator++()
+    {
+        ++it_;
+        return *this;
+    }
+
+    const_iterator
+    operator++(int)
+    {
+        auto temp = *this;
+        ++(*this);
+        return temp;
+    }
+
+    const_iterator&
+    operator--()
+    {
+        --it_;
+        return *this;
+    }
+
+    const_iterator
+    operator--(int)
+    {
+        auto temp = *this;
+        --(*this);
+        return temp;
+    }
+};
+
+template<class Allocator>
+basic_streambuf<Allocator>::const_buffers_type::const_buffers_type(
+    basic_streambuf const& sb)
+    : sb_(&sb)
+{
+}
+
+template<class Allocator>
+auto
+basic_streambuf<Allocator>::const_buffers_type::begin() const ->
+    const_iterator
+{
+    return const_iterator{*sb_, sb_->list_.begin()};
+}
+
+template<class Allocator>
+auto
+basic_streambuf<Allocator>::const_buffers_type::end() const ->
+    const_iterator
+{
+    return const_iterator{*sb_, sb_->out_ ==
+        sb_->list_.end() ? sb_->list_.end() :
+            std::next(sb_->out_)};
+}
+
+//------------------------------------------------------------------------------
+
+template<class Allocator>
+class basic_streambuf<Allocator>::mutable_buffers_type::const_iterator
+{
+    basic_streambuf const* sb_ = nullptr;
+    typename list_type::const_iterator it_;
+
+public:
+    using value_type =
+        typename mutable_buffers_type::value_type;
+    using pointer = value_type const*;
+    using reference = value_type;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category =
+        std::bidirectional_iterator_tag;
+
+    const_iterator() = default;
+    const_iterator(const_iterator&& other) = default;
+    const_iterator(const_iterator const& other) = default;
+    const_iterator& operator=(const_iterator&& other) = default;
+    const_iterator& operator=(const_iterator const& other) = default;
+
+    const_iterator(basic_streambuf const& sb,
+            typename list_type::const_iterator const& it)
+        : sb_(&sb)
+        , it_(it)
+    {
+    }
+
+    bool
+    operator==(const_iterator const& other) const
+    {
+        return sb_ == other.sb_ && it_ == other.it_;
+    }
+
+    bool
+    operator!=(const_iterator const& other) const
+    {
+        return !(*this == other);
+    }
+
+    reference
+    operator*() const
+    {
+        auto const& e = *it_;
+        return value_type{e.data(),
+            &e == &*std::prev(sb_->list_.end()) ?
+                sb_->out_end_ : e.size()} +
+                   (&e == &*sb_->out_ ? sb_->out_pos_ : 0);
+    }
+
+    pointer
+    operator->() const = delete;
+
+    const_iterator&
+    operator++()
+    {
+        ++it_;
+        return *this;
+    }
+
+    const_iterator
+    operator++(int)
+    {
+        auto temp = *this;
+        ++(*this);
+        return temp;
+    }
+
+    const_iterator&
+    operator--()
+    {
+        --it_;
+        return *this;
+    }
+
+    const_iterator
+    operator--(int)
+    {
+        auto temp = *this;
+        --(*this);
+        return temp;
+    }
+};
+
+template<class Allocator>
+basic_streambuf<Allocator>::mutable_buffers_type::mutable_buffers_type(
+    basic_streambuf const& sb)
+    : sb_(&sb)
+{
+}
+
+template<class Allocator>
+auto
+basic_streambuf<Allocator>::mutable_buffers_type::begin() const ->
+    const_iterator
+{
+    return const_iterator{*sb_, sb_->out_};
+}
+
+template<class Allocator>
+auto
+basic_streambuf<Allocator>::mutable_buffers_type::end() const ->
+    const_iterator
+{
+    return const_iterator{*sb_, sb_->list_.end()};
+}
+
+//------------------------------------------------------------------------------
+
+template<class Allocator>
+basic_streambuf<Allocator>::~basic_streambuf()
+{
+    delete_list();
+}
+
+template<class Allocator>
+basic_streambuf<Allocator>::
+basic_streambuf(basic_streambuf&& other)
+    : empty_base_optimization<allocator_type>(
+        std::move(other.member()))
+    , alloc_size_(other.alloc_size_)
+    , in_size_(other.in_size_)
+    , in_pos_(other.in_pos_)
+    , out_pos_(other.out_pos_)
+    , out_end_(other.out_end_)
+{
+    auto const at_end =
+        other.out_ == other.list_.end();
+    list_ = std::move(other.list_);
+    out_ = at_end ? list_.end() : other.out_;
+    other.in_size_ = 0;
+    other.out_ = other.list_.end();
+    other.in_pos_ = 0;
+    other.out_pos_ = 0;
+    other.out_end_ = 0;
+}
+
+template<class Allocator>
+basic_streambuf<Allocator>::
+basic_streambuf(basic_streambuf&& other,
+        allocator_type const& alloc)
+    : basic_streambuf(other.alloc_size_, alloc)
+{
+    using boost::asio::buffer_copy;
+    if(this->member() != other.member())
+        commit(buffer_copy(prepare(other.size()), other.data()));
+    else
+        move_assign(other, std::true_type{});
+}
+
+template<class Allocator>
+auto
+basic_streambuf<Allocator>::operator=(
+    basic_streambuf&& other) -> basic_streambuf&
+{
+    if(this == &other)
+        return *this;
+    // VFALCO If any memory allocated we could use it first?
+    clear();
+    alloc_size_ = other.alloc_size_;
+    move_assign(other, std::integral_constant<bool,
+        alloc_traits::propagate_on_container_move_assignment::value>{});
+    return *this;
+}
+
+template<class Allocator>
+basic_streambuf<Allocator>::
+basic_streambuf(basic_streambuf const& other)
+    : basic_streambuf(other.alloc_size_,
+        alloc_traits::select_on_container_copy_construction(other.member()))
+{
+    commit(boost::asio::buffer_copy(prepare(other.size()), other.data()));
+}
+
+template<class Allocator>
+basic_streambuf<Allocator>::
+basic_streambuf(basic_streambuf const& other,
+        allocator_type const& alloc)
+    : basic_streambuf(other.alloc_size_, alloc)
+{
+    commit(boost::asio::buffer_copy(prepare(other.size()), other.data()));
+}
+
+template<class Allocator>
+auto
+basic_streambuf<Allocator>::operator=(
+    basic_streambuf const& other) ->
+        basic_streambuf&
+{
+    if(this == &other)
+        return *this;
+    using boost::asio::buffer_copy;
+    clear();
+    copy_assign(other, std::integral_constant<bool,
+        alloc_traits::propagate_on_container_copy_assignment::value>{});
+    commit(buffer_copy(prepare(other.size()), other.data()));
+    return *this;
+}
+
+template<class Allocator>
+template<class OtherAlloc>
+basic_streambuf<Allocator>::basic_streambuf(
+    basic_streambuf<OtherAlloc> const& other)
+    : basic_streambuf(other.alloc_size_)
+{
+    using boost::asio::buffer_copy;
+    commit(buffer_copy(prepare(other.size()), other.data()));
+}
+
+template<class Allocator>
+template<class OtherAlloc>
+basic_streambuf<Allocator>::basic_streambuf(
+    basic_streambuf<OtherAlloc> const& other,
+        allocator_type const& alloc)
+    : basic_streambuf(other.alloc_size_, alloc)
+{
+    using boost::asio::buffer_copy;
+    commit(buffer_copy(prepare(other.size()), other.data()));
+}
+
+template<class Allocator>
+template<class OtherAlloc>
+auto
+basic_streambuf<Allocator>::operator=(
+    basic_streambuf<OtherAlloc> const& other) ->
+        basic_streambuf&
+{
+    using boost::asio::buffer_copy;
+    clear();
+    commit(buffer_copy(prepare(other.size()), other.data()));
+    return *this;
+}
+
+template<class Allocator>
+basic_streambuf<Allocator>::basic_streambuf(
+        std::size_t alloc_size, Allocator const& alloc)
+    : empty_base_optimization<allocator_type>(alloc)
+    , out_(list_.end())
+    , alloc_size_(alloc_size)
+{
+    if(alloc_size <= 0)
+        throw std::invalid_argument(
+            "basic_streambuf: invalid alloc_size");
+}
+
+template<class Allocator>
+auto
+basic_streambuf<Allocator>::prepare(size_type n) ->
+    mutable_buffers_type
+{
+    iterator pos = out_;
+    if(pos != list_.end())
+    {
+        auto const avail = pos->size() - out_pos_;
+        if(n > avail)
+        {
+            n -= avail;
+            out_end_ = pos->size();
+            while(++pos != list_.end())
+            {
+                if(n < pos->size())
+                {
+                    out_end_ = n;
+                    n = 0;
+                    ++pos;
+                    break;
+                }
+                n -= pos->size();
+            }
+        }
+        else
+        {
+            ++pos;
+            out_end_ = out_pos_ + n;
+            n = 0;
+        }
+    }
+
+    if(n > 0)
+    {
+        assert(pos == list_.end());
+        for(;;)
+        {
+            auto const size = std::max(alloc_size_, n);
+            auto& e = *reinterpret_cast<element*>(
+                alloc_traits::allocate(this->member(),
+                    size + sizeof(element)));
+            alloc_traits::construct(this->member(), &e, size);
+            list_.push_back(e);
+            if(out_ == list_.end())
+            {
+                out_ = list_.iterator_to(e);
+                debug_check();
+            }
+            if(n <= size)
+            {
+                out_end_ = n;
+                debug_check();
+                break;
+            }
+            n -= size;
+            debug_check();
+        }
+    }
+    else
+    {
+        while(pos != list_.end())
+        {
+            auto& e = *pos++;
+            list_.erase(list_.iterator_to(e));
+            auto const len = e.size() + sizeof(e);
+            alloc_traits::destroy(this->member(), &e);
+            alloc_traits::deallocate(this->member(),
+                reinterpret_cast<std::uint8_t*>(&e), len);
+        }
+        debug_check();
+    }
+
+    return mutable_buffers_type(*this);
+}
+
+template<class Allocator>
+void
+basic_streambuf<Allocator>::commit(size_type n)
+{
+    if(list_.empty())
+        return;
+    if(out_ == list_.end())
+        return;
+    auto const last = std::prev(list_.end());
+    while(out_ != last)
+    {
+        auto const avail =
+            out_->size() - out_pos_;
+        if(n < avail)
+        {
+            out_pos_ += n;
+            in_size_ += n;
+            debug_check();
+            return;
+        }
+        ++out_;
+        n -= avail;
+        out_pos_ = 0;
+        in_size_ += avail;
+        debug_check();
+    }
+
+    n = std::min(n, out_end_ - out_pos_);
+    out_pos_ += n;
+    in_size_ += n;
+    if(out_pos_ == out_->size())
+    {
+        ++out_;
+        out_pos_ = 0;
+        out_end_ = 0;
+    }
+    debug_check();
+}
+
+template<class Allocator>
+auto
+basic_streambuf<Allocator>::data() const ->
+    const_buffers_type
+{
+    return const_buffers_type(*this);
+}
+
+template<class Allocator>
+void
+basic_streambuf<Allocator>::consume(size_type n)
+{
+    if(list_.empty())
+        return;
+
+    auto pos = list_.begin();
+    for(;;)
+    {
+        if(pos != out_)
+        {
+            auto const avail = pos->size() - in_pos_;
+            if(n < avail)
+            {
+                in_size_ -= n;
+                in_pos_ += n;
+                debug_check();
+                break;
+            }
+            n -= avail;
+            in_size_ -= avail;
+            in_pos_ = 0;
+            debug_check();
+
+            element& e = *pos++;
+            list_.erase(list_.iterator_to(e));
+            auto const len = e.size() + sizeof(e);
+            alloc_traits::destroy(this->member(), &e);
+            alloc_traits::deallocate(this->member(),
+                reinterpret_cast<std::uint8_t*>(&e), len);
+        }
+        else
+        {
+            auto const avail = out_pos_ - in_pos_;
+            if(n < avail)
+            {
+                in_size_ -= n;
+                in_pos_ += n;
+            }
+            else
+            {
+                in_size_ -= avail;
+                if(out_pos_ != out_end_||
+                    out_ != list_.iterator_to(list_.back()))
+                {
+                    in_pos_ = out_pos_;
+                }
+                else
+                {
+                    // Use the whole buffer now.
+                    // Alternatively we could deallocate it.
+                    in_pos_ = 0;
+                    out_pos_ = 0;
+                    out_end_ = 0;
+                }
+            }
+            debug_check();
+            break;
+        }
+    }
+}
+
+template<class Allocator>
+void
+basic_streambuf<Allocator>::clear()
+{
+    delete_list();
+    list_.clear();
+    out_ = list_.begin();
+    in_size_ = 0;
+    in_pos_ = 0;
+    out_pos_ = 0;
+    out_end_ = 0;
+}
+
+template<class Allocator>
+void
+basic_streambuf<Allocator>::
+move_assign(basic_streambuf& other, std::false_type)
+{
+    using boost::asio::buffer_copy;
+    if(this->member() != other.member())
+    {
+        commit(buffer_copy(prepare(other.size()), other.data()));
+        other.clear();
+    }
+    else
+        move_assign(other, std::true_type{});
+}
+
+template<class Allocator>
+void
+basic_streambuf<Allocator>::
+move_assign(basic_streambuf& other, std::true_type)
+{
+    this->member() = std::move(other.member());
+    auto const at_end =
+        other.out_ == other.list_.end();
+    list_ = std::move(other.list_);
+    out_ = at_end ? list_.end() : other.out_;
+
+    in_size_ = other.in_size_;
+    in_pos_ = other.in_pos_;
+    out_pos_ = other.out_pos_;
+    out_end_ = other.out_end_;
+
+    other.in_size_ = 0;
+    other.out_ = other.list_.end();
+    other.in_pos_ = 0;
+    other.out_pos_ = 0;
+    other.out_end_ = 0;
+}
+
+template<class Allocator>
+void
+basic_streambuf<Allocator>::
+copy_assign(basic_streambuf const& other, std::false_type)
+{
+}
+
+template<class Allocator>
+void
+basic_streambuf<Allocator>::
+copy_assign(basic_streambuf const& other, std::true_type)
+{
+    this->member() = other.member();
+}
+
+template<class Allocator>
+void
+basic_streambuf<Allocator>::delete_list()
+{
+    for(auto iter = list_.begin(); iter != list_.end();)
+    {
+        auto& e = *iter++;
+        auto const n = e.size() + sizeof(e);
+        alloc_traits::destroy(this->member(), &e);
+        alloc_traits::deallocate(this->member(),
+            reinterpret_cast<std::uint8_t*>(&e), n);
+    }
+}
+
+// Returns the number of bytes which can be
+// prepared without causing a memory allocation.
+template<class Allocator>
+std::size_t
+basic_streambuf<Allocator>::prepare_size() const
+{
+    auto pos = out_;
+    if(pos == list_.end())
+        return 0;
+    auto n = pos->size() - out_pos_;
+    while(++pos != list_.end())
+        n += pos->size();
+    return n;
+}
+
+template<class Allocator>
+void
+basic_streambuf<Allocator>::debug_check() const
+{
+#ifndef NDEBUG
+    if(list_.empty())
+    {
+        assert(in_pos_ == 0);
+        assert(in_size_ == 0);
+        assert(out_pos_ == 0);
+        assert(out_end_ == 0);
+        assert(out_ == list_.end());
+        return;
+    }
+
+    auto const& front = list_.front();
+
+    assert(in_pos_ < front.size());
+
+    if(out_ == list_.end())
+    {
+        assert(out_pos_ == 0);
+        assert(out_end_ == 0);
+    }
+    else
+    {
+        auto const& out = *out_;
+        auto const& back = list_.back();
+
+        assert(out_end_ <= back.size());
+        assert(out_pos_ <  out.size());
+        assert(&out != &front || out_pos_ >= in_pos_);
+        assert(&out != &front || out_pos_ - in_pos_ == in_size_);
+        assert(&out != &back  || out_pos_ <= out_end_);
+    }
+#endif
+}
+
+template<class Alloc, class T>
+basic_streambuf<Alloc>&
+operator<<(basic_streambuf<Alloc>& buf, T const& t)
+{
+    using boost::asio::buffer;
+    using boost::asio::buffer_copy;
+    std::stringstream ss;
+    ss << t;
+    auto const& s = ss.str();
+    buf.commit(buffer_copy(buf.prepare(s.size()),
+        boost::asio::buffer(s)));
+    return buf;
+}
+
+//------------------------------------------------------------------------------
+
+template<class Allocator>
+std::size_t
+read_size_helper(basic_streambuf<
+    Allocator> const& streambuf, std::size_t max_size)
+{
+    return std::min<std::size_t>(max_size,
+        std::max<std::size_t>(512, streambuf.prepare_size()));
+}
+
+template<class Allocator>
+std::string
+to_string(basic_streambuf<Allocator> const& streambuf)
+{
+    using boost::asio::buffer;
+    using boost::asio::buffer_copy;
+    std::string s;
+    s.resize(streambuf.size());
+    buffer_copy(
+        buffer(&s[0], s.size()), streambuf.data());
+    return s;
+}
+
+} // beast
+
+#endif

beast/asio/impl/streambuf_readstream.ipp

@@ -0,0 +1,265 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_STREAMBUF_READSTREAM_IPP_INLUDED
+#define BEAST_ASIO_STREAMBUF_READSTREAM_IPP_INLUDED
+
+#include <beast/asio/async_completion.h>
+#include <beast/asio/bind_handler.h>
+#include <beast/asio/handler_alloc.h>
+#include <beast/asio/type_check.h>
+
+namespace beast {
+
+template<class Stream, class Streambuf>
+template<class MutableBufferSequence, class Handler>
+class streambuf_readstream<
+    Stream, Streambuf>::read_some_op
+{
+    using alloc_type =
+        handler_alloc<char, Handler>;
+
+    struct data
+    {
+        streambuf_readstream& brs;
+        MutableBufferSequence bs;
+        Handler h;
+        int state = 0;
+
+        template<class DeducedHandler>
+        data(DeducedHandler&& h_,
+            streambuf_readstream& brs_,
+                MutableBufferSequence const& bs_)
+            : brs(brs_)
+            , bs(bs_)
+            , h(std::forward<DeducedHandler>(h_))
+        {
+        }
+    };
+
+    std::shared_ptr<data> d_;
+
+public:
+    read_some_op(read_some_op&&) = default;
+    read_some_op(read_some_op const&) = default;
+
+    template<class DeducedHandler, class... Args>
+    read_some_op(DeducedHandler&& h, Args&&... args)
+        : d_(std::allocate_shared<data>(alloc_type{h},
+            std::forward<DeducedHandler>(h),
+                std::forward<Args>(args)...))
+    {
+        (*this)(error_code{}, 0);
+    }
+
+    void
+    operator()(error_code const& ec,
+        std::size_t bytes_transferred);
+
+    friend
+    auto asio_handler_allocate(
+        std::size_t size, read_some_op* op)
+    {
+        return boost_asio_handler_alloc_helpers::
+            allocate(size, op->d_->h);
+    }
+
+    friend
+    auto asio_handler_deallocate(
+        void* p, std::size_t size, read_some_op* op)
+    {
+        return boost_asio_handler_alloc_helpers::
+            deallocate(p, size, op->d_->h);
+    }
+
+    friend
+    auto asio_handler_is_continuation(read_some_op* op)
+    {
+        return boost_asio_handler_cont_helpers::
+            is_continuation(op->d_->h);
+    }
+
+    template <class Function>
+    friend
+    auto asio_handler_invoke(Function&& f, read_some_op* op)
+    {
+        return boost_asio_handler_invoke_helpers::
+            invoke(f, op->d_->h);
+    }
+};
+
+template<class Stream, class Streambuf>
+template<class MutableBufferSequence, class Handler>
+void
+streambuf_readstream<Stream, Streambuf>::
+read_some_op<MutableBufferSequence, Handler>::operator()(
+    error_code const& ec, std::size_t bytes_transferred)
+{
+    auto& d = *d_;
+    while(! ec && d.state != 99)
+    {
+        switch(d.state)
+        {
+        case 0:
+            if(d.brs.sb_.size() == 0)
+            {
+                d.state =
+                    d.brs.size_ > 0 ? 2 : 1;
+                break;
+            }
+            d.state = 4;
+            d.brs.get_io_service().post(
+                bind_handler(std::move(*this), ec, 0));
+            return;
+
+        case 1:
+            // read (unbuffered)
+            d.state = 99;
+            d.brs.next_layer_.async_read_some(
+                d.bs, std::move(*this));
+            return;
+
+        case 2:
+            // read
+            d.state = 3;
+            d.brs.next_layer_.async_read_some(
+                d.brs.sb_.prepare(d.brs.size_),
+                    std::move(*this));
+            return;
+
+        // got data
+        case 3:
+            d.state = 4;
+            d.brs.sb_.commit(bytes_transferred);
+            break;
+
+        // copy
+        case 4:
+            bytes_transferred =
+                boost::asio::buffer_copy(
+                    d.bs, d.brs.sb_.data());
+            d.brs.sb_.consume(bytes_transferred);
+            // call handler
+            d.state = 99;
+            break;
+        }
+    }
+    d.h(ec, bytes_transferred);
+}
+
+//------------------------------------------------------------------------------
+
+template<class Stream, class Streambuf>
+template<class... Args>
+streambuf_readstream<Stream, Streambuf>::
+streambuf_readstream(Args&&... args)
+    : next_layer_(std::forward<Args>(args)...)
+{
+    static_assert(is_Stream<next_layer_type>::value,
+        "Stream requirements not met");
+    static_assert(is_Streambuf<Streambuf>::value,
+        "Streambuf requirements not met");
+}
+
+template<class Stream, class Streambuf>
+template<class ConstBufferSequence, class WriteHandler>
+auto
+streambuf_readstream<Stream, Streambuf>::
+async_write_some(ConstBufferSequence const& buffers,
+    WriteHandler&& handler)
+{
+    static_assert(is_ConstBufferSequence<
+        ConstBufferSequence>::value,
+            "ConstBufferSequence requirements not met");
+    static_assert(is_Handler<WriteHandler,
+        void(error_code, std::size_t)>::value,
+            "WriteHandler requirements not met");
+    return next_layer_.async_write_some(buffers,
+        std::forward<WriteHandler>(handler));
+}
+
+template<class Stream, class Streambuf>
+template<class MutableBufferSequence>
+std::size_t
+streambuf_readstream<Stream, Streambuf>::
+read_some(
+    MutableBufferSequence const& buffers)
+{
+    static_assert(is_MutableBufferSequence<
+        MutableBufferSequence>::value,
+            "MutableBufferSequence requirements not met");
+    error_code ec;
+    auto n = read_some(buffers, ec);
+    if(ec)
+        throw boost::system::system_error{ec};
+    return n;
+}
+
+template<class Stream, class Streambuf>
+template<class MutableBufferSequence>
+std::size_t
+streambuf_readstream<Stream, Streambuf>::
+read_some(MutableBufferSequence const& buffers,
+    error_code& ec)
+{
+    static_assert(is_MutableBufferSequence<
+        MutableBufferSequence>::value,
+            "MutableBufferSequence requirements not met");
+    using boost::asio::buffer_size;
+    using boost::asio::buffer_copy;
+    if(buffer_size(buffers) == 0)
+        return 0;
+    if(size_ == 0)
+        return next_layer_.read_some(buffers, ec);
+    if(sb_.size() == 0)
+    {
+        sb_.commit(next_layer_.read_some(
+            sb_.prepare(size_), ec));
+        if(ec)
+            return 0;
+    }
+    auto bytes_transferred =
+        buffer_copy(buffers, sb_.data());
+    sb_.consume(bytes_transferred);
+    return bytes_transferred;
+}
+
+template<class Stream, class Streambuf>
+template<class MutableBufferSequence, class ReadHandler>
+auto
+streambuf_readstream<Stream, Streambuf>::
+async_read_some(
+    MutableBufferSequence const& buffers,
+        ReadHandler&& handler)
+{
+    static_assert(is_MutableBufferSequence<
+        MutableBufferSequence>::value,
+            "MutableBufferSequence requirements not met");
+    beast::async_completion<
+        ReadHandler, void(error_code, std::size_t)
+            > completion(handler);
+    read_some_op<MutableBufferSequence,
+        decltype(completion.handler)>{
+            completion.handler, *this, buffers};
+    return completion.result.get();
+}
+
+} // beast
+
+#endif

beast/asio/io_latency_probe.h

@@ -20,15 +20,14 @@
 #ifndef BEAST_ASIO_IO_LATENCY_PROBE_H_INCLUDED
 #define BEAST_ASIO_IO_LATENCY_PROBE_H_INCLUDED
 
+#include <boost/asio/deadline_timer.hpp>
+#include <boost/asio/io_service.hpp>
+#include <boost/config.hpp>
 #include <chrono>
 #include <condition_variable>
 #include <mutex>
 #include <stdexcept>
 
-#include <boost/asio/deadline_timer.hpp>
-#include <boost/asio/io_service.hpp>
-#include <boost/config.hpp>
-
 namespace beast {
 
 /** Measures handler latency on an io_service queue. */

beast/asio/prepare_buffers.h

@@ -0,0 +1,345 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_PREPARE_BUFFERS_H_INLUDED
+#define BEAST_ASIO_PREPARE_BUFFERS_H_INLUDED
+
+#include <boost/asio/buffer.hpp>
+#include <algorithm>
+#include <cstdint>
+#include <iterator>
+#include <stdexcept>
+#include <utility>
+
+namespace beast {
+
+/** Get a trimmed const buffer.
+
+    The new buffer starts at the beginning of the passed
+    buffer. Ownership of the underlying memory is not
+    transferred.
+*/
+inline
+boost::asio::const_buffer
+prepare_buffer(std::size_t n,
+    boost::asio::const_buffer buffer)
+{
+    using boost::asio::buffer_cast;
+    using boost::asio::buffer_size;
+    return { buffer_cast<void const*>(buffer),
+        std::min(n, buffer_size(buffer)) };
+}
+
+/** Get a trimmed mutable buffer.
+
+    The new buffer starts at the beginning of the passed
+    buffer. Ownership of the underlying memory is not
+    transferred.
+*/
+inline
+boost::asio::mutable_buffer
+prepare_buffer(std::size_t n,
+    boost::asio::mutable_buffer buffer)
+{
+    using boost::asio::buffer_cast;
+    using boost::asio::buffer_size;
+    return { buffer_cast<void*>(buffer),
+        std::min(n, buffer_size(buffer)) };
+}
+
+/** Wrapper to produce a trimmed buffer sequence.
+
+    This wraps a buffer sequence to efficiently present a shorter
+    subset of the original list of buffers starting with the first
+    byte of the original sequence.
+
+    @tparam BufferSequence The buffer sequence to wrap.
+*/
+template<class BufferSequence>
+class prepared_buffers
+{
+    using iter_type =
+        typename BufferSequence::const_iterator;
+
+    BufferSequence bs_;
+    iter_type back_;
+    iter_type end_;
+    std::size_t size_;
+
+    template<class Deduced>
+    prepared_buffers(Deduced&& other,
+            std::size_t nback, std::size_t nend)
+        : bs_(std::forward<Deduced>(other).bs_)
+        , back_(std::next(bs_.begin(), nback))
+        , end_(std::next(bs_.begin(), nend))
+        , size_(other.size_)
+    {
+    }
+
+public:
+    /// The type for each element in the list of buffers.
+    using value_type =
+        typename std::iterator_traits<iter_type>::value_type;
+
+    class const_iterator;
+
+    /// Move constructor.
+    prepared_buffers(prepared_buffers&&);
+
+    /// Copy constructor.
+    prepared_buffers(prepared_buffers const&);
+
+    /// Move assignment.
+    prepared_buffers& operator=(prepared_buffers&&);
+
+    /// Copy assignment.
+    prepared_buffers& operator=(prepared_buffers const&);
+
+    /** Construct a wrapped buffer sequence.
+
+        @param n The maximum number of bytes in the wrapped sequence.
+        If this is larger than the size of buffers, the wrapped
+        sequence will represent the entire input sequence.
+
+        @param buffers The buffer sequence to wrap. A copy of the sequence
+        will be made, but ownership of the underlying memory is not transferred.
+    */
+    prepared_buffers(std::size_t n, BufferSequence const& buffers);
+
+    /// Get a bidirectional iterator to the first element.
+    const_iterator
+    begin() const;
+
+    /// Get a bidirectional iterator for one past the last element.
+    const_iterator
+    end() const;
+
+private:
+    void
+    setup(std::size_t n)
+    {
+        for(end_ = bs_.begin(); end_ != bs_.end(); ++end_)
+        {
+            auto const len =
+                boost::asio::buffer_size(*end_);
+            if(n <= len)
+            {
+                size_ = n;
+                back_ = end_++;
+                return;
+            }
+            n -= len;
+        }
+        size_ = 0;
+        back_ = end_;
+    }
+};
+
+/// A bidirectional iterator type that may be used to read elements.
+template<class BufferSequence>
+class prepared_buffers<BufferSequence>::const_iterator
+{
+    friend class prepared_buffers<BufferSequence>;
+
+    using iter_type =
+        typename BufferSequence::const_iterator;
+
+    prepared_buffers const* b_;
+    typename BufferSequence::const_iterator it_;
+
+public:
+    using value_type =
+        typename std::iterator_traits<iter_type>::value_type;
+    using pointer = value_type const*;
+    using reference = value_type;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category =
+        std::bidirectional_iterator_tag;
+
+    const_iterator() = default;
+    const_iterator(const_iterator&& other) = default;
+    const_iterator(const_iterator const& other) = default;
+    const_iterator& operator=(const_iterator&& other) = default;
+    const_iterator& operator=(const_iterator const& other) = default;
+
+    bool
+    operator==(const_iterator const& other) const
+    {
+        return b_ == other.b_ && it_ == other.it_;
+    }
+
+    bool
+    operator!=(const_iterator const& other) const
+    {
+        return !(*this == other);
+    }
+
+    reference
+    operator*() const
+    {
+        if(it_ == b_->back_)
+            return prepare_buffer(b_->size_, *it_);
+        return *it_;
+    }
+
+    pointer
+    operator->() const = delete;
+
+    const_iterator&
+    operator++()
+    {
+        ++it_;
+        return *this;
+    }
+
+    const_iterator
+    operator++(int)
+    {
+        auto temp = *this;
+        ++(*this);
+        return temp;
+    }
+
+    const_iterator&
+    operator--()
+    {
+        --it_;
+        return *this;
+    }
+
+    const_iterator
+    operator--(int)
+    {
+        auto temp = *this;
+        --(*this);
+        return temp;
+    }
+
+private:
+    const_iterator(prepared_buffers const& b,
+            bool at_end)
+        : b_(&b)
+        , it_(at_end ? b.end_ : b.bs_.begin())
+    {
+    }
+};
+
+template<class BufferSequence>
+prepared_buffers<BufferSequence>::
+prepared_buffers(prepared_buffers&& other)
+    : prepared_buffers(std::move(other),
+        std::distance<iter_type>(other.bs_.begin(), other.back_),
+        std::distance<iter_type>(other.bs_.begin(), other.end_))
+{
+}
+
+template<class BufferSequence>
+prepared_buffers<BufferSequence>::
+prepared_buffers(prepared_buffers const& other)
+    : prepared_buffers(other,
+        std::distance<iter_type>(other.bs_.begin(), other.back_),
+        std::distance<iter_type>(other.bs_.begin(), other.end_))
+{
+}
+
+template<class BufferSequence>
+auto
+prepared_buffers<BufferSequence>::
+operator=(prepared_buffers&& other) ->
+    prepared_buffers&
+{
+    auto const nback = std::distance<iter_type>(
+        other.bs_.begin(), other.back_);
+    auto const nend = std::distance<iter_type>(
+        other.bs_.begin(), other.end_);
+    bs_ = std::move(other.bs_);
+    back_ = std::next(bs_.begin(), nback);
+    end_ = std::next(bs_.begin(), nend);
+    size_ = other.size_;
+    return *this;
+}
+
+template<class BufferSequence>
+auto
+prepared_buffers<BufferSequence>::
+operator=(prepared_buffers const& other) ->
+    prepared_buffers&
+{
+    auto const nback = std::distance<iter_type>(
+        other.bs_.begin(), other.back_);
+    auto const nend = std::distance<iter_type>(
+        other.bs_.begin(), other.end_);
+    bs_ = other.bs_;
+    back_ = std::next(bs_.begin(), nback);
+    end_ = std::next(bs_.begin(), nend);
+    size_ = other.size_;
+    return *this;
+}
+
+template<class BufferSequence>
+prepared_buffers<BufferSequence>::
+prepared_buffers(std::size_t n, BufferSequence const& bs)
+    : bs_(bs)
+{
+    setup(n);
+}
+
+template<class BufferSequence>
+auto
+prepared_buffers<BufferSequence>::begin() const ->
+    const_iterator
+{
+    return const_iterator{*this, false};
+}
+
+template<class BufferSequence>
+auto
+prepared_buffers<BufferSequence>::end() const ->
+    const_iterator
+{
+    return const_iterator{*this, true};
+}
+
+//------------------------------------------------------------------------------
+
+/** Return a trimmed, wrapped buffer sequence.
+
+    This function returns a new buffer sequence which wraps the provided
+    buffer sequence and efficiently presents a shorter subset of the
+    original list of buffers starting with the first byte of the original
+    sequence.
+
+    @param n The maximum number of bytes in the wrapped sequence. If this
+    is larger than the size of buffers, the wrapped sequence will represent
+    the entire input sequence.
+
+    @param buffers The buffer sequence to wrap. A copy of the sequence
+    will be made, but ownership of the underlying memory is not transferred.
+*/
+template<class BufferSequence>
+inline
+prepared_buffers<BufferSequence>
+prepare_buffers(std::size_t n, BufferSequence const& buffers)
+{
+    return prepared_buffers<BufferSequence>(n, buffers);
+}
+
+} // beast
+
+#endif

beast/asio/src/test/beast_asio_bind_handler_test.cpp

@@ -17,20 +17,12 @@
 */
 //==============================================================================
 
-// LIBS: boost_system
-
-#if BEAST_INCLUDE_BEASTCONFIG
-#include <BeastConfig.h>
-#endif
-
 #include <beast/unit_test/suite.h>
-
 #include <beast/asio/bind_handler.h>
-
 #include <functional>
 
 namespace beast {
-namespace asio {
+namespace test {
 
 class bind_handler_test : public unit_test::suite
 {
@@ -51,5 +43,6 @@ public:
 
 BEAST_DEFINE_TESTSUITE(bind_handler,asio,beast);
 
-}
-}
+} // test
+} // beast
+

beast/asio/src/test/beast_asio_buffers_test.cpp

@@ -0,0 +1,362 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <beast/asio/append_buffers.h>
+#include <beast/asio/buffers_adapter.h>
+#include <beast/asio/prepare_buffers.h>
+#include <beast/asio/consuming_buffers.h>
+#include <beast/asio/streambuf.h>
+#include <beast/asio/static_streambuf.h>
+#include <beast/asio/streambuf_readstream.h>
+#include <beast/unit_test/suite.h>
+#include <boost/asio/buffer.hpp>
+#include <array>
+#include <list>
+#include <string>
+
+namespace beast {
+namespace test {
+
+class buffers_test : public unit_test::suite
+{
+public:
+    template<class ConstBufferSequence>
+    static
+    std::string
+    to_string(ConstBufferSequence const& bs)
+    {
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        std::string s;
+        s.reserve(buffer_size(bs));
+        for(auto const& b : bs)
+            s.append(buffer_cast<char const*>(b),
+                buffer_size(b));
+        return s;
+    }
+
+    void testStreambuf()
+    {
+        using boost::asio::buffer;
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        std::string const s = "Hello, world";
+        expect(s.size() == 12);
+        for(std::size_t i = 1; i < 12; ++i) {
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        for(std::size_t t = 1; t < 4; ++ t) {
+        for(std::size_t u = 1; u < 4; ++ u) {
+        std::size_t z = s.size() - (x + y);
+        std::size_t v = s.size() - (t + u);
+        {
+            streambuf sb(i);
+            decltype(sb)::mutable_buffers_type d;
+            d = sb.prepare(z); expect(buffer_size(d) == z);
+            d = sb.prepare(0); expect(buffer_size(d) == 0);
+            d = sb.prepare(y); expect(buffer_size(d) == y);
+            d = sb.prepare(x); expect(buffer_size(d) == x);
+            sb.commit(buffer_copy(d, buffer(s.data(), x)));
+            expect(sb.size() == x);
+            expect(buffer_size(sb.data()) == sb.size());
+            d = sb.prepare(x); expect(buffer_size(d) == x);
+            d = sb.prepare(0); expect(buffer_size(d) == 0);
+            d = sb.prepare(z); expect(buffer_size(d) == z);
+            d = sb.prepare(y); expect(buffer_size(d) == y);
+            sb.commit(buffer_copy(d, buffer(s.data()+x, y)));
+            sb.commit(1);
+            expect(sb.size() == x + y);
+            expect(buffer_size(sb.data()) == sb.size());
+            d = sb.prepare(x); expect(buffer_size(d) == x);
+            d = sb.prepare(y); expect(buffer_size(d) == y);
+            d = sb.prepare(0); expect(buffer_size(d) == 0);
+            d = sb.prepare(z); expect(buffer_size(d) == z);
+            sb.commit(buffer_copy(d, buffer(s.data()+x+y, z)));
+            sb.commit(2);
+            expect(sb.size() == x + y + z);
+            expect(buffer_size(sb.data()) == sb.size());
+            expect(to_string(sb.data()) == s);
+            sb.consume(t);
+            d = sb.prepare(0); expect(buffer_size(d) == 0);
+            expect(to_string(sb.data()) == s.substr(t, std::string::npos));
+            sb.consume(u);
+            expect(to_string(sb.data()) == s.substr(t + u, std::string::npos));
+            sb.consume(v);
+            expect(to_string(sb.data()) == "");
+            sb.consume(1);
+            d = sb.prepare(0); expect(buffer_size(d) == 0);
+        }
+        }}}}}
+    }
+
+    void testBuffersAdapter()
+    {
+        using boost::asio::buffer;
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        using boost::asio::const_buffer;
+        using boost::asio::mutable_buffer;
+        char buf[12];
+        std::string const s = "Hello, world";
+        expect(s.size() == sizeof(buf));
+        for(std::size_t i = 1; i < 4; ++i) {
+        for(std::size_t j = 1; j < 4; ++j) {
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        for(std::size_t t = 1; t < 4; ++ t) {
+        for(std::size_t u = 1; u < 4; ++ u) {
+        std::size_t k = sizeof(buf) - (i + j);
+        std::size_t z = sizeof(buf) - (x + y);
+        std::size_t v = sizeof(buf) - (t + u);
+        {
+            std::memset(buf, 0, sizeof(buf));
+            std::array<mutable_buffer, 3> bs{{
+                mutable_buffer{&buf[0], i},
+                mutable_buffer{&buf[i], j},
+                mutable_buffer{&buf[i+j], k}}};
+            buffers_adapter<decltype(bs)> ba(std::move(bs));
+            expect(ba.max_size() == sizeof(buf));
+            decltype(ba)::mutable_buffers_type d;
+            d = ba.prepare(z); expect(buffer_size(d) == z);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            d = ba.prepare(y); expect(buffer_size(d) == y);
+            d = ba.prepare(x); expect(buffer_size(d) == x);
+            ba.commit(buffer_copy(d, buffer(s.data(), x)));
+            expect(ba.size() == x);
+            expect(ba.max_size() == sizeof(buf) - x);
+            expect(buffer_size(ba.data()) == ba.size());
+            d = ba.prepare(x); expect(buffer_size(d) == x);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            d = ba.prepare(z); expect(buffer_size(d) == z);
+            d = ba.prepare(y); expect(buffer_size(d) == y);
+            ba.commit(buffer_copy(d, buffer(s.data()+x, y)));
+            ba.commit(1);
+            expect(ba.size() == x + y);
+            expect(ba.max_size() == sizeof(buf) - (x + y));
+            expect(buffer_size(ba.data()) == ba.size());
+            d = ba.prepare(x); expect(buffer_size(d) == x);
+            d = ba.prepare(y); expect(buffer_size(d) == y);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            d = ba.prepare(z); expect(buffer_size(d) == z);
+            ba.commit(buffer_copy(d, buffer(s.data()+x+y, z)));
+            ba.commit(2);
+            expect(ba.size() == x + y + z);
+            expect(ba.max_size() == 0);
+            expect(buffer_size(ba.data()) == ba.size());
+            expect(to_string(ba.data()) == s);
+            ba.consume(t);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            expect(to_string(ba.data()) == s.substr(t, std::string::npos));
+            ba.consume(u);
+            expect(to_string(ba.data()) == s.substr(t + u, std::string::npos));
+            ba.consume(v);
+            expect(to_string(ba.data()) == "");
+            ba.consume(1);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            try
+            {
+                ba.prepare(1);
+                fail();
+            }
+            catch(...)
+            {
+                pass();
+            }
+        }
+        }}}}}}
+    }
+
+    void testConsuming()
+    {
+        using boost::asio::buffer;
+        using boost::asio::const_buffer;
+        char buf[12];
+        std::string const s = "Hello, world";
+        expect(s.size() == sizeof(buf));
+        buffer_copy(buffer(buf), buffer(s));
+        expect(to_string(buffer(buf)) == s);
+        for(std::size_t i = 1; i < 4; ++i) {
+        for(std::size_t j = 1; j < 4; ++j) {
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        std::size_t k = sizeof(buf) - (i + j);
+        std::size_t z = sizeof(buf) - (x + y);
+        {
+            std::array<const_buffer, 3> bs{{
+                const_buffer{&buf[0], i},
+                const_buffer{&buf[i], j},
+                const_buffer{&buf[i+j], k}}};
+            consuming_buffers<decltype(bs)> cb(bs);
+            expect(to_string(cb) == s);
+            cb.consume(0);
+            expect(to_string(cb) == s);
+            cb.consume(x);
+            expect(to_string(cb) == s.substr(x));
+            cb.consume(y);
+            expect(to_string(cb) == s.substr(x+y));
+            cb.consume(z);
+            expect(to_string(cb) == "");
+            cb.consume(1);
+            expect(to_string(cb) == "");
+        }
+        }}}}
+    }
+
+    void testStaticBuffers()
+    {
+        using boost::asio::buffer;
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        char buf[12];
+        std::string const s = "Hello, world";
+        expect(s.size() == sizeof(buf));
+        for(std::size_t i = 1; i < 4; ++i) {
+        for(std::size_t j = 1; j < 4; ++j) {
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        for(std::size_t t = 1; t < 4; ++ t) {
+        for(std::size_t u = 1; u < 4; ++ u) {
+        std::size_t z = sizeof(buf) - (x + y);
+        std::size_t v = sizeof(buf) - (t + u);
+        {
+            std::memset(buf, 0, sizeof(buf));
+            static_streambuf_n<sizeof(buf)> ba;
+            decltype(ba)::mutable_buffers_type d;
+            d = ba.prepare(z); expect(buffer_size(d) == z);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            d = ba.prepare(y); expect(buffer_size(d) == y);
+            d = ba.prepare(x); expect(buffer_size(d) == x);
+            ba.commit(buffer_copy(d, buffer(s.data(), x)));
+            expect(ba.size() == x);
+            expect(buffer_size(ba.data()) == ba.size());
+            d = ba.prepare(x); expect(buffer_size(d) == x);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            d = ba.prepare(z); expect(buffer_size(d) == z);
+            d = ba.prepare(y); expect(buffer_size(d) == y);
+            ba.commit(buffer_copy(d, buffer(s.data()+x, y)));
+            ba.commit(1);
+            expect(ba.size() == x + y);
+            expect(buffer_size(ba.data()) == ba.size());
+            d = ba.prepare(x); expect(buffer_size(d) == x);
+            d = ba.prepare(y); expect(buffer_size(d) == y);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            d = ba.prepare(z); expect(buffer_size(d) == z);
+            ba.commit(buffer_copy(d, buffer(s.data()+x+y, z)));
+            ba.commit(2);
+            expect(ba.size() == x + y + z);
+            expect(buffer_size(ba.data()) == ba.size());
+            expect(to_string(ba.data()) == s);
+            ba.consume(t);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            expect(to_string(ba.data()) == s.substr(t, std::string::npos));
+            ba.consume(u);
+            expect(to_string(ba.data()) == s.substr(t + u, std::string::npos));
+            ba.consume(v);
+            expect(to_string(ba.data()) == "");
+            ba.consume(1);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            try
+            {
+                ba.prepare(1);
+                fail();
+            }
+            catch(...)
+            {
+                pass();
+            }
+        }
+        }}}}}}
+    }
+
+    void testAppendBuffers()
+    {
+        using boost::asio::buffer_size;
+        using boost::asio::const_buffer;
+        char buf[10];
+        std::list<const_buffer> b1;
+        std::vector<const_buffer> b2{
+            const_buffer{buf+0, 1},
+            const_buffer{buf+1, 2}};
+        std::list<const_buffer> b3;
+        std::array<const_buffer, 3> b4{{
+            const_buffer{buf+3, 1},
+            const_buffer{buf+4, 2},
+            const_buffer{buf+6, 3}}};
+        std::list<const_buffer> b5{
+            const_buffer{buf+9, 1}};
+        std::list<const_buffer> b6;
+        auto bs = append_buffers(
+            b1, b2, b3, b4, b5, b6);
+        expect(buffer_size(bs) == 10);
+        std::vector<const_buffer> v;
+        for(auto iter = std::make_reverse_iterator(bs.end());
+                iter != std::make_reverse_iterator(bs.begin()); ++iter)
+            v.emplace_back(*iter);
+        expect(buffer_size(bs) == 10);
+        decltype(bs) bs2(bs);
+        auto bs3(std::move(bs));
+        bs = bs2;
+        bs3 = std::move(bs2);
+        {
+            streambuf sb1, sb2;
+            expect(buffer_size(append_buffers(
+                sb1.prepare(5), sb2.prepare(7))) == 12);
+            sb1.commit(5);
+            sb2.commit(7);
+            expect(buffer_size(append_buffers(
+                sb1.data(), sb2.data())) == 12);
+        }
+    }
+
+    void testClipBuffers()
+    {
+        using boost::asio::const_buffer;
+        std::string const s = "Hello, world";
+        expect(s.size() == 12);
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        std::size_t z = s.size() - (x + y);
+        {
+            std::array<const_buffer, 3> bs{{
+                const_buffer{&s[0], x},
+                const_buffer{&s[x], y},
+                const_buffer{&s[x+y], z}}};
+            for(std::size_t i = 0; i <= s.size() + 1; ++i)
+                expect(to_string(prepare_buffers(i, bs)) ==
+                    s.substr(0, i));
+        }
+        }}
+    }
+
+    void run() override
+    {
+        testStreambuf();
+        testBuffersAdapter();
+        testConsuming();
+        testStaticBuffers();
+
+        testAppendBuffers();
+        testClipBuffers();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(buffers,asio,beast);
+
+} // test
+} // beast

beast/asio/src/test/beast_asio_error_test.cpp

@@ -17,22 +17,22 @@
 */
 //==============================================================================
 
-#include <beast/asio/error.h>
+#include <beast/asio/ssl_error.h>
 #include <beast/unit_test/suite.h>
 #include <string>
 
 namespace beast {
-namespace asio {
 
 class error_test : public unit_test::suite
 {
 public:
-    void run ()
+    void run()
     {
         {
-            boost::system::error_code ec = boost::system::error_code (335544539,
+            boost::system::error_code ec =
+                boost::system::error_code (335544539,
                     boost::asio::error::get_ssl_category ());
-            std::string const s = beast::asio::asio_message (ec);
+            std::string const s = beast::error_message_with_ssl(ec);
             expect(s == " (20,0,219) error:140000DB:SSL routines:SSL routines:short read");
         }
     }
@@ -40,5 +40,4 @@ public:
 
 BEAST_DEFINE_TESTSUITE(error,asio,beast);
 
-}
-}
+} // beast

beast/asio/ssl_error.h

@@ -17,43 +17,56 @@
 */
 //==============================================================================
 
-#include <beast/asio/error.h>
+#ifndef BEAST_ASIO_SSL_ERROR_H_INCLUDED
+#define BEAST_ASIO_SSL_ERROR_H_INCLUDED
+
+#include <boost/asio.hpp>
+//#include <boost/asio/error.hpp> // Causes error with WinSock.h
+#include <boost/asio/ssl/error.hpp>
 #include <boost/lexical_cast.hpp>
 
 namespace beast {
-namespace asio {
-
-// This buffer must be at least 120 bytes, most examples use 256.
-// https://www.openssl.org/docs/crypto/ERR_error_string.html
-static std::uint32_t const errorBufferSize (256);
 
+/** Returns a human readable message if the error code is SSL related. */
+template<class = void>
 std::string
-asio_message (boost::system::error_code const& ec)
+error_message_with_ssl(boost::system::error_code const& ec)
 {
     std::string error;
 
-    if (ec.category () == boost::asio::error::get_ssl_category ())
+    if (ec.category() == boost::asio::error::get_ssl_category())
     {
         error = " ("
-            + boost::lexical_cast<std::string> (ERR_GET_LIB (ec.value ()))
+            + boost::lexical_cast<std::string>(ERR_GET_LIB (ec.value ()))
             + ","
-            + boost::lexical_cast<std::string> (ERR_GET_FUNC (ec.value ()))
+            + boost::lexical_cast<std::string>(ERR_GET_FUNC (ec.value ()))
             + ","
-            + boost::lexical_cast<std::string> (ERR_GET_REASON (ec.value ()))
+            + boost::lexical_cast<std::string>(ERR_GET_REASON (ec.value ()))
             + ") ";
 
-        //
-        char buf[errorBufferSize];
-        ::ERR_error_string_n (ec.value (), buf, errorBufferSize);
+        // This buffer must be at least 120 bytes, most examples use 256.
+        // https://www.openssl.org/docs/crypto/ERR_error_string.html
+        char buf[256];
+        ::ERR_error_string_n(ec.value (), buf, sizeof(buf));
         error += buf;
     }
     else
     {
-        error = ec.message ();
+        error = ec.message();
     }
 
     return error;
 }
 
+/** Returns `true` if the error code is a SSL "short read." */
+inline
+bool
+is_short_read(boost::system::error_code const& ec)
+{
+    return (ec.category() == boost::asio::error::get_ssl_category())
+        && (ERR_GET_REASON(ec.value()) == SSL_R_SHORT_READ);
 }
-}
+
+} // beast
+
+#endif

beast/asio/static_streambuf.h

@@ -0,0 +1,471 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_STATIC_STREAMBUF_H_INLUDED
+#define BEAST_ASIO_STATIC_STREAMBUF_H_INLUDED
+
+#include <boost/asio/buffer.hpp>
+#include <boost/utility/base_from_member.hpp>
+#include <algorithm>
+#include <cstring>
+#include <iterator>
+#include <stdexcept>
+
+namespace beast {
+
+/** A `Streambuf` with a fixed size internal buffer.
+
+    Ownership of the underlying storage belongs to the derived class.
+
+    @note Variables are usually declared using the template class
+    `static_streambuf_n`; however, to reduce the number of instantiations
+    of template functions receiving static stream buffer arguments in a
+    deduced context, the signature of the receiving function should use
+    `static_streambuf`.
+*/
+class static_streambuf
+{
+#if GENERATING_DOCS
+private:
+#else
+protected:
+#endif
+    std::uint8_t* in_;
+    std::uint8_t* out_;
+    std::uint8_t* last_;
+    std::uint8_t* end_;
+
+public:
+    class const_buffers_type;
+    class mutable_buffers_type;
+
+#if GENERATING_DOCS
+private:
+#endif
+    static_streambuf(
+        static_streambuf const& other) noexcept = delete;
+    static_streambuf& operator=(
+        static_streambuf const&) noexcept = delete;
+#if GENERATING_DOCS
+public:
+#endif
+
+    /// Returns the largest size output sequence possible.
+    std::size_t
+    max_size() const
+    {
+        return end_ - in_;
+    }
+
+    /// Get the size of the input sequence.
+    std::size_t
+    size() const
+    {
+        return out_ - in_;
+    }
+
+    /** Get a list of buffers that represents the output sequence, with the given size.
+
+        @throws std::length_error if the size would exceed the limit
+        imposed by the underlying mutable buffer sequence.
+    */
+    mutable_buffers_type
+    prepare(std::size_t n);
+
+    /// Move bytes from the output sequence to the input sequence.
+    void
+    commit(std::size_t n)
+    {
+        out_ += std::min<std::size_t>(n, last_ - out_);
+    }
+
+    /// Get a list of buffers that represents the input sequence.
+    const_buffers_type
+    data() const;
+
+    /// Remove bytes from the input sequence.
+    void
+    consume(std::size_t n)
+    {
+        in_ += std::min<std::size_t>(n, out_ - in_);
+    }
+
+#if GENERATING_DOCS
+private:
+#else
+protected:
+#endif
+    static_streambuf(std::uint8_t* p, std::size_t n)
+    {
+        reset(p, n);
+    }
+
+    void
+    reset(std::uint8_t* p, std::size_t n)
+    {
+        in_ = p;
+        out_ = p;
+        last_ = p;
+        end_ = p + n;
+    }
+};
+
+//------------------------------------------------------------------------------
+
+/// The type used to represent the input sequence as a list of buffers.
+class static_streambuf::const_buffers_type
+{
+    std::size_t n_;
+    std::uint8_t const* p_;
+
+public:
+    using value_type = boost::asio::const_buffer;
+
+    class const_iterator;
+
+    const_buffers_type() = default;
+    const_buffers_type(
+        const_buffers_type const&) = default;
+    const_buffers_type& operator=(
+        const_buffers_type const&) = default;
+
+    const_iterator
+    begin() const;
+
+    const_iterator
+    end() const;
+
+private:
+    friend class static_streambuf;
+
+    const_buffers_type(
+            std::uint8_t const* p, std::size_t n)
+        : n_(n)
+        , p_(p)
+    {
+    }
+};
+
+class static_streambuf::const_buffers_type::const_iterator
+{
+    std::size_t n_;
+    std::uint8_t const* p_;
+
+public:
+    using value_type = boost::asio::const_buffer;
+    using pointer = value_type const*;
+    using reference = value_type;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category =
+        std::bidirectional_iterator_tag;
+
+    const_iterator() = default;
+    const_iterator(const_iterator&& other) = default;
+    const_iterator(const_iterator const& other) = default;
+    const_iterator& operator=(const_iterator&& other) = default;
+    const_iterator& operator=(const_iterator const& other) = default;
+
+    bool
+    operator==(const_iterator const& other) const
+    {
+        return p_ == other.p_;
+    }
+
+    bool
+    operator!=(const_iterator const& other) const
+    {
+        return !(*this == other);
+    }
+
+    reference
+    operator*() const
+    {
+        return value_type{p_, n_};
+    }
+
+    pointer
+    operator->() const = delete;
+
+    const_iterator&
+    operator++()
+    {
+        p_ += n_;
+        return *this;
+    }
+
+    const_iterator
+    operator++(int)
+    {
+        auto temp = *this;
+        ++(*this);
+        return temp;
+    }
+
+    const_iterator&
+    operator--()
+    {
+        p_ -= n_;
+        return *this;
+    }
+
+    const_iterator
+    operator--(int)
+    {
+        auto temp = *this;
+        --(*this);
+        return temp;
+    }
+
+private:
+    friend class const_buffers_type;
+
+    const_iterator(
+            std::uint8_t const* p, std::size_t n)
+        : n_(n)
+        , p_(p)
+    {
+    }
+};
+
+inline
+auto
+static_streambuf::const_buffers_type::begin() const ->
+    const_iterator
+{
+    return const_iterator{p_, n_};
+}
+
+inline
+auto
+static_streambuf::const_buffers_type::end() const ->
+    const_iterator
+{
+    return const_iterator{p_ + n_, n_};
+}
+
+//------------------------------------------------------------------------------
+
+/// The type used to represent the output sequence as a list of buffers.
+class static_streambuf::mutable_buffers_type
+{
+    std::size_t n_;
+    std::uint8_t* p_;
+
+public:
+    using value_type = boost::asio::mutable_buffer;
+
+    class const_iterator;
+
+    mutable_buffers_type() = default;
+    mutable_buffers_type(
+        mutable_buffers_type const&) = default;
+    mutable_buffers_type& operator=(
+        mutable_buffers_type const&) = default;
+
+    const_iterator
+    begin() const;
+
+    const_iterator
+    end() const;
+
+private:
+    friend class static_streambuf;
+
+    mutable_buffers_type(
+            std::uint8_t* p, std::size_t n)
+        : n_(n)
+        , p_(p)
+    {
+    }
+};
+
+class static_streambuf::mutable_buffers_type::const_iterator
+{
+    std::size_t n_;
+    std::uint8_t* p_;
+
+public:
+    using value_type = boost::asio::mutable_buffer;
+    using pointer = value_type const*;
+    using reference = value_type;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category =
+        std::bidirectional_iterator_tag;
+
+    const_iterator() = default;
+    const_iterator(const_iterator&& other) = default;
+    const_iterator(const_iterator const& other) = default;
+    const_iterator& operator=(const_iterator&& other) = default;
+    const_iterator& operator=(const_iterator const& other) = default;
+
+    bool
+    operator==(const_iterator const& other) const
+    {
+        return p_ == other.p_;
+    }
+
+    bool
+    operator!=(const_iterator const& other) const
+    {
+        return !(*this == other);
+    }
+
+    reference
+    operator*() const
+    {
+        return value_type{p_, n_};
+    }
+
+    pointer
+    operator->() const = delete;
+
+    const_iterator&
+    operator++()
+    {
+        p_ += n_;
+        return *this;
+    }
+
+    const_iterator
+    operator++(int)
+    {
+        auto temp = *this;
+        ++(*this);
+        return temp;
+    }
+
+    const_iterator&
+    operator--()
+    {
+        p_ -= n_;
+        return *this;
+    }
+
+    const_iterator
+    operator--(int)
+    {
+        auto temp = *this;
+        --(*this);
+        return temp;
+    }
+
+private:
+    friend class mutable_buffers_type;
+
+    const_iterator(std::uint8_t* p, std::size_t n)
+        : n_(n)
+        , p_(p)
+    {
+    }
+};
+
+inline
+auto
+static_streambuf::mutable_buffers_type::begin() const ->
+    const_iterator
+{
+    return const_iterator{p_, n_};
+}
+
+inline
+auto
+static_streambuf::mutable_buffers_type::end() const ->
+    const_iterator
+{
+    return const_iterator{p_ + n_, n_};
+}
+
+//------------------------------------------------------------------------------
+
+inline
+auto
+static_streambuf::prepare(std::size_t n) ->
+    mutable_buffers_type
+{
+    if(n > static_cast<std::size_t>(end_ - out_))
+        throw std::length_error("no space in streambuf");
+    last_ = out_ + n;
+    return mutable_buffers_type{out_, n};
+}
+
+inline
+auto
+static_streambuf::data() const ->
+    const_buffers_type
+{
+    return const_buffers_type{in_,
+        static_cast<std::size_t>(out_ - in_)};
+}
+
+//------------------------------------------------------------------------------
+
+/** A `Streambuf` with a fixed size internal buffer.
+
+    @tparam N The number of bytes in the internal buffer.
+
+    @note To reduce the number of template instantiations when passing
+    objects of this type in a deduced context, the signature of the
+    receiving function should use `static_streambuf` instead.
+*/
+template<std::size_t N>
+class static_streambuf_n
+    : private boost::base_from_member<
+        std::array<std::uint8_t, N>>
+    , public static_streambuf
+{
+    using member_type = boost::base_from_member<
+        std::array<std::uint8_t, N>>;
+public:
+#if GENERATING_DOCS
+private:
+#endif
+    static_streambuf_n(
+        static_streambuf_n const&) = delete;
+    static_streambuf_n& operator=(
+        static_streambuf_n const&) = delete;
+#if GENERATING_DOCS
+public:
+#endif
+
+    /// Construct a static stream buffer.
+    static_streambuf_n()
+        : static_streambuf(
+            member_type::member.data(),
+                member_type::member.size())
+    {
+    }
+
+    /** Reset the stream buffer.
+
+        Postconditions:
+            The input sequence and output sequence are empty,
+            `max_size()` returns `N`.
+    */
+    void
+    reset()
+    {
+        static_streambuf::reset(
+            member_type::member.data(),
+                member_type::member.size());
+    }
+};
+
+} // beast
+
+#endif

beast/asio/streambuf.h

@@ -20,661 +20,12 @@
 #ifndef BEAST_ASIO_STREAMBUF_H_INCLUDED
 #define BEAST_ASIO_STREAMBUF_H_INCLUDED
 
-#include <beast/empty_base_optimization.h>
-#include <boost/asio/buffer.hpp>
-#include <boost/intrusive/list.hpp>
-#include <boost/iterator/transform_iterator.hpp>
-#include <algorithm>
-#include <cassert>
-#include <memory>
-#include <exception>
-#include <type_traits>
-#include <string>
-#include <utility>
+#include <beast/asio/basic_streambuf.h>
 
 namespace beast {
-namespace asio {
-
-/** Implements asio::streambuf interface using multiple buffers. */
-template <class Allocator>
-class basic_streambuf
-    : private empty_base_optimization<Allocator>
-{
-public:
-    using size_type = typename std::allocator_traits<Allocator>::size_type;
-    using const_buffer = boost::asio::const_buffer;
-    using mutable_buffer = boost::asio::mutable_buffer;
-
-private:
-    class element;
-
-    using alloc_traits = std::allocator_traits<Allocator>;
-    using list_type = typename boost::intrusive::make_list <element,
-        boost::intrusive::constant_time_size <true>>::type;
-    using iterator = typename list_type::iterator;
-    using const_iterator = typename list_type::const_iterator;
-
-    /*  These diagrams illustrate the layout and state variables.
-
-        Input and output contained entirely in one element:
-
-        0                            out_
-        |<-------------+------------------------------------------->|
-      in_pos_       out_pos_                                     out_end_
-
-
-        Output contained in first and second elements:
-
-                     out_
-        |<------+----------+------->|   |<----------+-------------->|
-              in_pos_   out_pos_                 out_end_
-
-
-        Output contained in the second element:
-
-                                                     out_
-        |<------------+------------>|   |<----+-------------------->|
-                    in_pos_                out_pos_              out_end_
-
-
-        Output contained in second and third elements:
-
-                                     out_
-        |<-----+-------->|   |<-------+------>|   |<--------------->|
-             in_pos_               out_pos_                      out_end_
-
-
-        Input sequence is empty:
-
-                     out_
-        |<------+------------------>|   |<-----------+------------->|
-             out_pos_                             out_end_
-              in_pos_
-
-
-        Output sequence is empty:
-
-                                                     out_
-        |<------+------------------>|   |<------+------------------>|
-              in_pos_                        out_pos_
-                                             out_end_
-
-
-        The end of output can point to the end of an element.
-        But out_pos_ should never point to the end:
-
-                                                     out_
-        |<------+------------------>|   |<------+------------------>|
-              in_pos_                        out_pos_            out_end_
-
-
-        When the input sequence entirely fills the last element and
-        the output sequence is empty, out_ will point to the end of
-        the list of buffers, and out_pos_ and out_end_ will be 0:
-
-
-        |<------+------------------>|   out_     == list_.end()
-              in_pos_                   out_pos_ == 0
-                                        out_end_ == 0
-    */
-
-    list_type list_;
-    size_type block_size_;
-    size_type block_size_next_;
-    size_type in_size_ = 0; // size of the input sequence
-    iterator out_;          // element that contains out_pos_
-    size_type in_pos_ = 0;  // input offset in list_.front()
-    size_type out_pos_ = 0; // output offset in *out_
-    size_type out_end_ = 0; // output end offset in list_.back()
-
-public:
-    class const_buffers_type;
-    class mutable_buffers_type;
-
-    basic_streambuf (basic_streambuf const& other) = delete;
-    basic_streambuf& operator= (basic_streambuf const& other) = delete;
-    basic_streambuf& operator= (basic_streambuf&& other) = delete;
-
-    ~basic_streambuf();
-
-    explicit
-    basic_streambuf(std::size_t block_size = 16*1024,
-        Allocator const& alloc = Allocator{});
-
-    basic_streambuf (basic_streambuf&& other);
-
-    /** Get the maximum size of the basic_streambuf. */
-    size_type
-    max_size() const
-    {
-        return std::numeric_limits<std::size_t>::max();
-    }
-
-    /** Get the size of the input sequence. */
-    size_type
-    size() const
-    {
-        return in_size_;
-    }
-
-    /** Get a list of buffers that represents the output sequence, with the given size. */
-    mutable_buffers_type
-    prepare (size_type n);
-
-    /** Move bytes from the output sequence to the input sequence. */
-    void
-    commit (size_type n);
-
-    /** Get a list of buffers that represents the input sequence. */
-    const_buffers_type
-    data() const;
-
-    /** Remove bytes from the input sequence. */
-    void
-    consume (size_type n);
-
-private:
-    void
-    debug_check() const;
-};
-
-//------------------------------------------------------------------------------
-
-template <class Allocator>
-class basic_streambuf<Allocator>::element
-    : public boost::intrusive::list_base_hook <
-        boost::intrusive::link_mode <boost::intrusive::normal_link>>
-{
-private:
-    size_type const size_;  // size of the allocation minus sizeof(element)
-
-public:
-    element (element const&) = delete;
-    element& operator= (element const&) = delete;
-
-    explicit
-    element (size_type block_size)
-        : size_(block_size)
-        { }
-
-    size_type
-    size() const
-    {
-        return size_;
-    }
-
-    size_type
-    alloc_size() const
-    {
-        return size_ + sizeof(*this);
-    }
-
-    char*
-    data() const
-    {
-        return const_cast<char*>(
-            reinterpret_cast<char const*>(this+1));
-    }
-};
-
-//------------------------------------------------------------------------------
-
-template <class Allocator>
-class basic_streambuf<Allocator>::const_buffers_type
-{
-public:
-    using value_type = const_buffer;
-
-private:
-    struct transform
-    {
-        using argument_type = element;
-        using result_type = value_type;
-
-        basic_streambuf const* streambuf_ = nullptr;
-
-        transform() = default;
-
-        explicit
-        transform (basic_streambuf const& streambuf)
-            : streambuf_ (&streambuf)
-        {
-        }
-
-        value_type const
-        operator() (element const& e) const;
-    };
-
-    basic_streambuf const* streambuf_ = nullptr;
-
-public:
-    using const_iterator = boost::transform_iterator<
-        transform, typename list_type::const_iterator,
-            value_type, value_type>;
-
-    const_buffers_type() = default;
-    const_buffers_type (const_buffers_type const&) = default;
-    const_buffers_type& operator= (const_buffers_type const&) = default;
-
-    const_iterator
-    begin() const
-    {
-        return const_iterator (streambuf_->list_.begin(),
-            transform(*streambuf_));
-    }
-
-    const_iterator
-    end() const
-    {
-        return const_iterator (streambuf_->out_ ==
-            streambuf_->list_.end() ? streambuf_->list_.end() :
-                std::next(streambuf_->out_), transform(*streambuf_));
-    }
-
-private:
-    friend class basic_streambuf;
-
-    explicit
-    const_buffers_type (basic_streambuf const& streambuf);
-};
-
-template <class Allocator>
-basic_streambuf<Allocator>::const_buffers_type::const_buffers_type (
-    basic_streambuf const& streambuf)
-    : streambuf_ (&streambuf)
-{
-}
-
-template <class Allocator>
-auto
-basic_streambuf<Allocator>::const_buffers_type::
-    transform::operator() (element const& e) const ->
-        value_type const
-{
-    return value_type (e.data(),
-        (streambuf_->out_ == streambuf_->list_.end() ||
-            &e != &*streambuf_->out_) ? e.size() : streambuf_->out_pos_) +
-                (&e == &*streambuf_->list_.begin() ?
-                    streambuf_->in_pos_ : 0);
-}
-
-//------------------------------------------------------------------------------
-
-template <class Allocator>
-class basic_streambuf<Allocator>::mutable_buffers_type
-{
-public:
-    using value_type = mutable_buffer;
-
-private:
-    struct transform
-    {
-        using argument_type = element;
-        using result_type = value_type;
-
-        basic_streambuf const* streambuf_ = nullptr;
-
-        transform() = default;
-
-        explicit
-        transform (basic_streambuf const& streambuf)
-            : streambuf_ (&streambuf)
-        {
-        }
-
-        value_type const
-        operator() (element const& e) const;
-    };
-
-    basic_streambuf const* streambuf_;
-
-public:
-    using const_iterator = boost::transform_iterator<
-        transform, typename list_type::const_iterator,
-            value_type, value_type>;
-
-    mutable_buffers_type() = default;
-    mutable_buffers_type (mutable_buffers_type const&) = default;
-    mutable_buffers_type& operator= (mutable_buffers_type const&) = default;
-
-    const_iterator
-    begin() const
-    {
-        return const_iterator (streambuf_->out_,
-            transform(*streambuf_));
-    }
-
-    const_iterator
-    end() const
-    {
-        return const_iterator (streambuf_->list_.end(),
-            transform(*streambuf_));
-    }
-
-private:
-    friend class basic_streambuf;
-    mutable_buffers_type (basic_streambuf const& streambuf);
-};
-
-template <class Allocator>
-basic_streambuf<Allocator>::mutable_buffers_type::mutable_buffers_type (
-    basic_streambuf const& streambuf)
-    : streambuf_ (&streambuf)
-{
-}
-
-template <class Allocator>
-auto
-basic_streambuf<Allocator>::mutable_buffers_type::
-    transform::operator() (element const& e) const ->
-        value_type const
-{
-    return value_type (e.data(), &e == &*std::prev(streambuf_->list_.end()) ?
-        streambuf_->out_end_ : e.size()) + (&e == &*streambuf_->out_ ?
-            streambuf_->out_pos_ : 0);
-}
-
-//------------------------------------------------------------------------------
-
-template <class Allocator>
-basic_streambuf<Allocator>::~basic_streambuf()
-{
-    for(auto iter = list_.begin(); iter != list_.end();)
-    {
-        auto& e = *iter++;
-        size_type const n = e.alloc_size();
-        alloc_traits::destroy(this->member(), &e);
-        alloc_traits::deallocate(this->member(),
-            reinterpret_cast<char*>(&e), n);
-    }
-}
-
-template <class Allocator>
-basic_streambuf<Allocator>::basic_streambuf(std::size_t block_size,
-        Allocator const& alloc)
-    : empty_base_optimization<Allocator>(alloc)
-    , block_size_ (block_size)
-    , block_size_next_ (block_size)
-    , out_ (list_.end())
-{
-    if (! (block_size > 0))
-        throw std::invalid_argument(
-            "basic_streambuf: invalid block_size");
-}
-
-template <class Allocator>
-basic_streambuf<Allocator>::basic_streambuf (basic_streambuf&& other)
-    : empty_base_optimization<Allocator>(other.member())
-    , list_ (std::move(other.list_))
-    , block_size_ (other.block_size_)
-    , block_size_next_ (other.block_size_next_)
-    , in_size_ (other.in_size_)
-    , out_ (other.out_)
-    , in_pos_ (other.in_pos_)
-    , out_pos_ (other.out_pos_)
-    , out_end_ (other.out_end_)
-{
-    other.in_size_ = 0;
-    other.out_ = other.list_.end();
-    other.in_pos_ = 0;
-    other.out_pos_ = 0;
-    other.out_end_ = 0;
-}
-
-template <class Allocator>
-auto
-basic_streambuf<Allocator>::prepare (size_type n) ->
-    mutable_buffers_type
-{
-    iterator pos = out_;
-    if (pos != list_.end())
-    {
-        auto const avail = pos->size() - out_pos_;
-        if (n > avail)
-        {
-            n -= avail;
-            while (++pos != list_.end())
-            {
-                if (n < pos->size())
-                {
-                    out_end_ = n;
-                    n = 0;
-                    ++pos;
-                    break;
-                }
-                out_end_ = pos->size();
-                n -= pos->size();
-            }
-        }
-        else
-        {
-            ++pos;
-            out_end_ = out_pos_ + n;
-            n = 0;
-        }
-        debug_check();
-    }
-
-    if (n > 0)
-    {
-        assert(pos == list_.end());
-        for(;;)
-        {
-            auto const avail = block_size_next_;
-            auto& e = *reinterpret_cast<element*>(alloc_traits::allocate(
-                this->member(), avail + sizeof(element)));
-            alloc_traits::construct(this->member(), &e, avail);
-            list_.push_back(e);
-            if (out_ == list_.end())
-            {
-                out_ = list_.iterator_to(e);
-                debug_check();
-            }
-            if (n <= avail)
-            {
-                out_end_ = n;
-                debug_check();
-                break;
-            }
-            n -= avail;
-        }
-    }
-    else
-    {
-        while (pos != list_.end())
-        {
-            auto& e = *pos++;
-            list_.erase(list_.iterator_to(e));
-            auto const len = e.alloc_size();
-            alloc_traits::destroy(this->member(), &e);
-            alloc_traits::deallocate(this->member(),
-                reinterpret_cast<char*>(&e), len);
-        }
-        debug_check();
-    }
-
-    return mutable_buffers_type (*this);
-}
-
-template <class Allocator>
-void
-basic_streambuf<Allocator>::commit (size_type n)
-{
-    if (list_.empty())
-        return;
-    if (out_ == list_.end())
-        return;
-    auto const last = std::prev(list_.end());
-    while (out_ != last)
-    {
-        auto const avail =
-            out_->size() - out_pos_;
-        if (n < avail)
-        {
-            out_pos_ += n;
-            in_size_ += n;
-            debug_check();
-            return;
-        }
-        ++out_;
-        n -= avail;
-        out_pos_ = 0;
-        in_size_ += avail;
-        debug_check();
-    }
-
-    n = std::min (n, out_end_ - out_pos_);
-    out_pos_ += n;
-    in_size_ += n;
-    if (out_pos_ == out_->size())
-    {
-        ++out_;
-        out_pos_ = 0;
-        out_end_ = 0;
-    }
-    debug_check();
-}
-
-template <class Allocator>
-auto
-basic_streambuf<Allocator>::data() const ->
-    const_buffers_type
-{
-    return const_buffers_type(*this);
-}
-
-template <class Allocator>
-void
-basic_streambuf<Allocator>::consume (size_type n)
-{
-    if (list_.empty())
-        return;
-
-    auto pos = list_.begin();
-    for(;;)
-    {
-        if (pos != out_)
-        {
-            auto const avail = pos->size() - in_pos_;
-            if (n < avail)
-            {
-                in_size_ -= n;
-                in_pos_ += n;
-                debug_check();
-                break;
-            }
-            n -= avail;
-            in_size_ -= avail;
-            in_pos_ = 0;
-            debug_check();
-
-            element& e = *pos++;
-            list_.erase(list_.iterator_to(e));
-            size_type const len = e.alloc_size();
-            alloc_traits::destroy(this->member(), &e);
-            alloc_traits::deallocate(this->member(),
-                reinterpret_cast<char*>(&e), len);
-        }
-        else
-        {
-            auto const avail = out_pos_ - in_pos_;
-            if (n < avail)
-            {
-                in_size_ -= n;
-                in_pos_ += n;
-            }
-            else
-            {
-                in_size_ -= avail;
-                if (out_pos_ != out_end_||
-                    out_ != list_.iterator_to(list_.back()))
-                {
-                    in_pos_ = out_pos_;
-                }
-                else
-                {
-                    // Use the whole buffer now.
-                    // Alternatively we could deallocate it.
-                    in_pos_ = 0;
-                    out_pos_ = 0;
-                    out_end_ = 0;
-                }
-            }
-            debug_check();
-            break;
-        }
-    }
-}
-
-template <class Allocator>
-void
-basic_streambuf<Allocator>::debug_check() const
-{
-#ifndef NDEBUG
-    if (list_.empty())
-    {
-        assert(in_pos_ == 0);
-        assert(in_size_ == 0);
-        assert(out_pos_ == 0);
-        assert(out_end_ == 0);
-        assert(out_ == list_.end());
-        return;
-    }
-
-    auto const& front = list_.front();
-
-    assert(in_pos_ < front.size());
-
-    if (out_ == list_.end())
-    {
-        assert(out_pos_ == 0);
-        assert(out_end_ == 0);
-    }
-    else
-    {
-        auto const& out = *out_;
-        auto const& back = list_.back();
-
-        assert(out_end_ <= back.size());
-        assert(out_pos_ <  out.size());
-        assert(&out != &front || out_pos_ >= in_pos_);
-        assert(&out != &front || out_pos_ - in_pos_ == in_size_);
-        assert(&out != &back  || out_pos_ <= out_end_);
-    }
-#endif
-}
-
-template <class Alloc, class T>
-basic_streambuf<Alloc>&
-operator<< (basic_streambuf<Alloc>& buf, T const& t)
-{
-    std::stringstream ss;
-    ss << t;
-    auto const& s = ss.str();
-    buf.commit(boost::asio::buffer_copy(
-        buf.prepare(s.size()), boost::asio::buffer(s)));
-    return buf;
-}
-
-//------------------------------------------------------------------------------
 
 using streambuf = basic_streambuf<std::allocator<char>>;
 
-/** Convert the entire basic_streambuf to a string.
-    @note It is more efficient to deal directly in the streambuf instead.
-*/
-template <class Allocator>
-std::string
-to_string (basic_streambuf<Allocator> const& buf)
-{
-    std::string s;
-    s.resize(buf.size());
-    boost::asio::buffer_copy(boost::asio::buffer(
-        &s[0], s.size()), buf.data());
-    return s;
-}
-
-}
-}
+} // beast
 
 #endif

beast/asio/streambuf_readstream.h

@@ -0,0 +1,259 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_STREAMBUF_READSTREAM_H_INLUDED
+#define BEAST_ASIO_STREAMBUF_READSTREAM_H_INLUDED
+
+#include <beast/asio/streambuf.h>
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/io_service.hpp>
+#include <boost/system/error_code.hpp>
+#include <cstdint>
+#include <utility>
+
+namespace beast {
+
+/** A `Stream` with attached `Streambuf` to buffer reads.
+
+    This wraps a `Stream` implementation so that calls to write are
+    passed through to the underlying stream, while calls to read will
+    first consume the input sequence stored in a `Streambuf` which
+    is part of the object.
+
+    The use-case for this class is different than that of the
+    `boost::asio::buffered_readstream`. It is designed to facilitate
+    the use of `boost::asio::read_until`, and to allow buffers
+    acquired during detection of handshakes to be made transparently
+    available to callers. A hypothetical implementation of the
+    buffered version of `boost::asio::ssl::stream::async_handshake`
+    could make use of this wrapper.
+
+    Uses:
+
+    * Transparently leave untouched input acquired in calls
+      to `boost::asio::read_until` behind for subsequent callers.
+
+    * "Preload" a stream with handshake input data acquired
+      from other sources.
+
+    Example:
+    @code
+    // Process the next HTTP headers on the stream,
+    // leaving excess bytes behind for the next call.
+    //
+    template<class Streambuf>
+    void process_http_message(
+        streambuf_readstream<Streambuf>& stream)
+    {
+        // Read up to and including the end of the HTTP
+        // headers, leaving the sequence in the stream's
+        // buffer. read_until may read past the end of the
+        // headers; the return value will include only the
+        // part up to the end of the delimiter.
+        //
+        std::size_t bytes_transferred =
+            boost::asio::read_until(
+                stream.next_layer(), stream.buffer(), "\r\n\r\n");
+
+        // Use prepare_buffers() to limit the input
+        // sequence to only the data up to and including
+        // the trailing "\r\n\r\n".
+        //
+        auto header_buffers = prepare_buffers(
+            bytes_transferred, stream.buffer().data());
+
+        ...
+
+        // Discard the portion of the input corresponding
+        // to the HTTP headers.
+        //
+        stream.buffer().consume(bytes_transferred);
+
+        // Everything we read from the stream
+        // is part of the content-body.
+    }
+    @endcode
+
+    @tparam Stream The type of stream to wrap.
+
+    @tparam Streambuf The type of stream buffer to use.
+*/
+template<class Stream,
+    class Streambuf = streambuf>
+class streambuf_readstream
+{
+    using error_code = boost::system::error_code;
+
+    template<class Buffers, class Handler>
+    class read_some_op;
+
+    Streambuf sb_;
+    std::size_t size_ = 0;
+    Stream next_layer_;
+
+public:
+    /// The type of the internal buffer
+    using streambuf_type = Streambuf;
+
+    /// The type of the next layer.
+    using next_layer_type =
+        std::remove_reference_t<Stream>;
+
+    /// The type of the lowest layer.
+    using lowest_layer_type =
+        typename next_layer_type::lowest_layer_type;
+
+    /// Move constructor.
+    streambuf_readstream(streambuf_readstream&&) = default;
+
+    /** Construct the wrapping stream.
+
+        @param args Parameters forwarded to the `Stream` constructor.
+    */
+    template<class... Args>
+    explicit
+    streambuf_readstream(Args&&... args);
+
+    /// Get a reference to the next layer.
+    next_layer_type&
+    next_layer()
+    {
+        return next_layer_;
+    }
+
+    /// Get a reference to the lowest layer.
+    lowest_layer_type&
+    lowest_layer()
+    {
+        return next_layer_.lowest_layer();
+    }
+
+    /// Get a const reference to the lowest layer.
+    lowest_layer_type const&
+    lowest_layer() const
+    {
+        return next_layer_.lowest_layer();
+    }
+
+    /// Get the io_service associated with the object.
+    boost::asio::io_service&
+    get_io_service()
+    {
+        return next_layer_.get_io_service();
+    }
+
+    /** Access the internal buffer.
+
+        The internal buffer is returned. It is possible for the
+        caller to break invariants with this function. For example,
+        by causing the internal buffer size to increase beyond
+        the caller defined maximum.
+    */
+    Streambuf&
+    buffer()
+    {
+        return sb_;
+    }
+
+    /** Access the internal buffer.
+
+        The internal buffer is returned. It is possible for the
+        caller to break invariants with this function. For example,
+        by causing the internal buffer size to increase beyond
+        the caller defined maximum.
+    */
+    Streambuf const&
+    buffer() const
+    {
+        return sb_;
+    }
+
+    /** Set the maximum buffer size.
+
+        This changes the maximum size of the internal buffer used
+        to hold read data. No bytes are discarded by this call. If
+        the buffer size is set to zero, no more data will be buffered.
+
+        Thread safety:
+            The caller is responsible for making sure the call is
+            made from the same implicit or explicit strand.
+
+        @param size The number of bytes in the read buffer.
+
+        @note This is a soft limit. If the new maximum size is smaller
+        than the amount of data in the buffer, no bytes are discarded.
+    */
+    void
+    reserve(std::size_t size)
+    {
+        size_ = size;
+    }
+
+    /// Write the given data to the stream. Returns the number of bytes written.
+    /// Throws an exception on failure.
+    template<class ConstBufferSequence>
+    std::size_t
+    write_some(ConstBufferSequence const& buffers)
+    {
+        return next_layer_.write_some(buffers);
+    }
+
+    /// Write the given data to the stream. Returns the number of bytes written,
+    /// or 0 if an error occurred.
+    template <class ConstBufferSequence>
+    std::size_t
+    write_some(ConstBufferSequence const& buffers,
+        error_code& ec)
+    {
+        return next_layer_.write_some(buffers, ec);
+    }
+
+    /// Start an asynchronous write. The data being written must be valid for the
+    /// lifetime of the asynchronous operation.
+    template<class ConstBufferSequence, class WriteHandler>
+    auto
+    async_write_some(ConstBufferSequence const& buffers,
+        WriteHandler&& handler);
+
+    /// Read some data from the stream. Returns the number of bytes read.
+    /// Throws an exception on failure.
+    template<class MutableBufferSequence>
+    std::size_t
+    read_some(MutableBufferSequence const& buffers);
+
+    /// Read some data from the stream. Returns the number of bytes read
+    /// or 0 if an error occurred.
+    template<class MutableBufferSequence>
+    std::size_t
+    read_some(MutableBufferSequence const& buffers,
+        error_code& ec);
+
+    /// Start an asynchronous read. The buffer into which the data will be read
+    /// must be valid for the lifetime of the asynchronous operation.
+    template<class MutableBufferSequence, class ReadHandler>
+    auto
+    async_read_some(MutableBufferSequence const& buffers,
+        ReadHandler&& handler);
+};
+
+} // beast
+
+#include <beast/asio/impl/streambuf_readstream.ipp>
+
+#endif

beast/asio/temp_buffer.h

@@ -0,0 +1,109 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_TEMP_BUFFER_H_INCLUDED
+#define BEAST_ASIO_TEMP_BUFFER_H_INCLUDED
+
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/detail/handler_alloc_helpers.hpp>
+#include <cstdlib>
+#include <memory>
+#include <utility>
+
+namespace beast {
+
+template<class Handler>
+class temp_buffer
+{
+    Handler& h_;
+    std::size_t n_ = 0;
+    std::uint8_t* p_ = nullptr;
+
+public:
+    explicit
+    temp_buffer(Handler& h)
+        : h_(h)
+    {
+    }
+
+    ~temp_buffer()
+    {
+        if(p_)
+            dealloc();
+    }
+
+    operator
+    boost::asio::const_buffer() const
+    {
+        return boost::asio::const_buffer{p_, n_};
+    }
+
+    operator
+    boost::asio::mutable_buffer() const
+    {
+        return boost::asio::mutable_buffer{p_, n_};
+    }
+
+    std::uint8_t*
+    data() const
+    {
+        return p_;
+    }
+
+    std::size_t
+    size()
+    {
+        return n_;
+    }
+
+    boost::asio::mutable_buffers_1
+    buffers() const
+    {
+        return boost::asio::mutable_buffers_1{
+            p_, n_};
+    }
+
+    void
+    alloc(std::size_t size)
+    {
+        if(n_ != size)
+        {
+            if(p_)
+                dealloc();
+            n_ = size;
+            if(n_ > 0)
+                p_ = reinterpret_cast<std::uint8_t*>(
+                    boost_asio_handler_alloc_helpers::
+                        allocate(n_, h_));
+        }
+    }
+
+    void
+    dealloc()
+    {
+        boost_asio_handler_alloc_helpers::
+            deallocate(p_, n_, h_);
+        p_ = nullptr;
+        n_ = 0;
+    }
+};
+
+} // beast
+
+#endif

beast/asio/type_check.h

@@ -0,0 +1,329 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_TYPE_CHECK_H_INCLUDED
+#define BEAST_ASIO_TYPE_CHECK_H_INCLUDED
+
+#include <beast/is_call_possible.h>
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/error.hpp>
+#include <boost/asio/io_service.hpp>
+#include <iterator>
+#include <beast/cxx17/type_traits.h>
+#include <utility>
+
+namespace beast {
+
+//------------------------------------------------------------------------------
+
+// Types that meet the requirements,
+// for use with std::declval only.
+//
+
+#if GENERATING_DOCS
+namespace detail {
+#else
+namespace concept {
+#endif
+
+template<class BufferType>
+struct BufferSequence
+{
+    using value_type = BufferType;
+    using const_iterator = BufferType const*;
+    ~BufferSequence();
+    BufferSequence(BufferSequence const&) = default;
+    const_iterator
+    begin() const noexcept;
+    const_iterator
+    end() const noexcept;
+};
+
+using ConstBufferSequence =
+    BufferSequence<boost::asio::const_buffer>;
+
+using MutableBufferSequence =
+    BufferSequence<boost::asio::mutable_buffer>;
+
+struct StreamHandler
+{
+    StreamHandler(StreamHandler const&) = default;
+    void
+    operator()(boost::system::error_code ec,
+        std::size_t);
+};
+
+using ReadHandler = StreamHandler;
+using WriteHandler = StreamHandler;
+
+} // concept
+
+// http://www.boost.org/doc/libs/1_60_0/doc/html/boost_asio/reference/ConstBufferSequence.html
+// http://www.boost.org/doc/libs/1_60_0/doc/html/boost_asio/reference/MutableBufferSequence.html
+//
+/// Determine if `T` meets the requirements of `BufferSequence`.
+template<class T, class BufferType>
+class is_BufferSequence
+{
+    template<class U, class R = std::is_convertible<
+        typename U::value_type, BufferType> >
+    static R check1(int);
+    template<class>
+    static std::false_type check1(...);
+    using type1 = decltype(check1<T>(0));
+
+    template<class U, class R = std::is_base_of<
+    #if 0
+        std::bidirectional_iterator_tag,
+            typename std::iterator_traits<
+                typename U::const_iterator>::iterator_category>>
+    #else
+        // workaround:
+        // boost::asio::detail::consuming_buffers::const_iterator
+        // is not bidirectional
+        std::forward_iterator_tag,
+            typename std::iterator_traits<
+                typename U::const_iterator>::iterator_category>>
+    #endif
+    static R check2(int);
+    template<class>
+    static std::false_type check2(...);
+    using type2 = decltype(check2<T>(0));
+
+    template<class U, class R = typename
+        std::is_convertible<decltype(
+            std::declval<U>().begin()),
+                typename U::const_iterator>::type>
+    static R check3(int);
+    template<class>
+    static std::false_type check3(...);
+    using type3 = decltype(check3<T>(0));
+
+    template<class U, class R = typename std::is_convertible<decltype(
+        std::declval<U>().end()),
+            typename U::const_iterator>::type>
+    static R check4(int);
+    template<class>
+    static std::false_type check4(...);
+    using type4 = decltype(check4<T>(0));
+
+public:
+    /// `true` if `T` meets the requirements.
+    static bool const value =
+        std::is_copy_constructible<T>::value &&
+        std::is_destructible<T>::value &&
+        type1::value && type2::value &&
+        type3::value && type4::value;
+};
+
+#if ! GENERATING_DOCS
+
+/// Determine if `T` meets the requirements of `ConstBufferSequence`.
+template<class T>
+using is_ConstBufferSequence =
+    is_BufferSequence<T, boost::asio::const_buffer>;
+static_assert(is_ConstBufferSequence<concept::ConstBufferSequence>::value, "");
+static_assert(! is_ConstBufferSequence<int>::value, "");
+
+/// Determine if `T` meets the requirements of `MutableBufferSequence`.
+template<class C>
+using is_MutableBufferSequence =
+    is_BufferSequence<C, boost::asio::mutable_buffer>;
+static_assert(is_MutableBufferSequence<concept::MutableBufferSequence>::value, "");
+static_assert(! is_MutableBufferSequence<int>::value, "");
+
+#endif
+
+//------------------------------------------------------------------------------
+
+/// Determine if `T` has the `get_io_service` member.
+template<class T>
+class has_get_io_service
+{
+    template<class U, class R = typename std::is_same<
+        decltype(std::declval<U>().get_io_service()),
+            boost::asio::io_service&>>
+    static R check(int);
+    template <class>
+    static std::false_type check(...);
+    using type = decltype(check<T>(0));
+
+public:
+    /// `true` if `T` meets the requirements.
+    static bool const value = type::value;
+};
+static_assert(! has_get_io_service<int>::value, "");
+
+// http://www.boost.org/doc/libs/1_60_0/doc/html/boost_asio/reference/AsyncReadStream.html
+//
+/// Determine if `T` meets the requirements of `AsyncReadStream`.
+template<class T>
+class is_AsyncReadStream
+{
+    template<class U, class R = decltype(
+        std::declval<U>().async_read_some(
+            std::declval<concept::MutableBufferSequence>(),
+                std::declval<concept::ReadHandler>()),
+                    std::true_type{})>
+    static R check(int);
+    template<class>
+    static std::false_type check(...);
+    using type = decltype(check<T>(0));
+
+public:
+    /// `true` if `T` meets the requirements.
+    static bool const value =
+        has_get_io_service<T>::value && type::value;
+};
+static_assert(! is_AsyncReadStream<int>::value, "");
+
+// http://www.boost.org/doc/libs/1_60_0/doc/html/boost_asio/reference/AsyncWriteStream.html
+//
+/// Determine if `T` meets the requirements of `AsyncWriteStream`.
+template<class T>
+class is_AsyncWriteStream
+{
+    template<class U, class R = decltype(
+        std::declval<U>().async_write_some(
+            std::declval<concept::ConstBufferSequence>(),
+                std::declval<concept::WriteHandler>()),
+                    std::true_type{})>
+    static R check(int);
+    template<class>
+    static std::false_type check(...);
+    using type = decltype(check<T>(0));
+
+public:
+    /// `true` if `T` meets the requirements.
+    static bool const value =
+        has_get_io_service<T>::value && type::value;
+};
+static_assert(! is_AsyncWriteStream<int>::value, "");
+
+// http://www.boost.org/doc/libs/1_60_0/doc/html/boost_asio/reference/SyncReadStream.html
+//
+/// Determine if `T` meets the requirements of `SyncReadStream`.
+template<class T>
+class is_SyncReadStream
+{
+    using error_code =
+        boost::system::error_code;
+
+    template<class U, class R = std::is_same<decltype(
+        std::declval<U>().read_some(
+            std::declval<concept::MutableBufferSequence>())),
+                std::size_t>>
+    static R check1(int);
+    template<class>
+    static std::false_type check1(...);
+    using type1 = decltype(check1<T>(0));
+
+    template<class U, class R = std::is_same<decltype(
+        std::declval<U>().read_some(
+            std::declval<concept::MutableBufferSequence>(),
+                std::declval<error_code&>())), std::size_t>>
+    static R check2(int);
+    template<class>
+    static std::false_type check2(...);
+    using type2 = decltype(check2<T>(0));
+
+public:
+    /// `true` if `T` meets the requirements.
+    static bool const value =
+        type1::value && type2::value;
+};
+static_assert(! is_SyncReadStream<int>::value, "");
+
+// http://www.boost.org/doc/libs/1_60_0/doc/html/boost_asio/reference/SyncWriteStream.html
+//
+/// Determine if `T` meets the requirements of `SyncWriterStream`.
+template<class T>
+class is_SyncWriteStream
+{
+    using error_code =
+        boost::system::error_code;
+
+    template<class U, class R = std::is_same<decltype(
+        std::declval<U>().write_some(
+            std::declval<concept::ConstBufferSequence>())),
+                std::size_t>>
+    static R check1(int);
+    template<class>
+    static std::false_type check1(...);
+    using type1 = decltype(check1<T>(0));
+
+    template<class U, class R = std::is_same<decltype(
+        std::declval<U>().write_some(
+            std::declval<concept::ConstBufferSequence>(),
+                std::declval<error_code&>())), std::size_t>>
+    static R check2(int);
+    template<class>
+    static std::false_type check2(...);
+    using type2 = decltype(check2<T>(0));
+
+public:
+    /// `true` if `T` meets the requirements.
+    static bool const value =
+        type1::value && type2::value;
+};
+static_assert(! is_SyncWriteStream<int>::value, "");
+
+/// Determine if `T` meets the requirements of `Stream`.
+template<class T>
+struct is_Stream
+{
+/// `true` if `T` meets the requirements.
+    static bool const value =
+        is_AsyncReadStream<T>::value &&
+        is_AsyncWriteStream<T>::value &&
+        is_SyncReadStream<T>::value &&
+        is_SyncWriteStream<T>::value;
+};
+
+/// Determine if `T` meets the requirements of `Streambuf`.
+template<class T, class = void>
+struct is_Streambuf : std::false_type {};
+template <class T>
+struct is_Streambuf<T, std::void_t<
+    // VFALCO TODO Add check for const_buffers_type, mutable_buffers_type, max_size(?)
+    std::integral_constant<bool,
+        is_MutableBufferSequence<decltype(
+            std::declval<T>().prepare(1))>::value>,
+    std::integral_constant<bool,
+        is_ConstBufferSequence<decltype(
+            std::declval<T>().data())>::value>,
+    decltype(std::declval<T>().commit(1), std::true_type{}),
+    decltype(std::declval<T>().consume(1), std::true_type{}),
+    std::is_same<decltype(
+        std::declval<T>().size()), std::size_t>
+>>:std::true_type{};
+
+#if ! GENERATING_DOCS
+
+/// Determine if `T` meets the requirements of `CompletionHandler`.
+template<class T, class Signature>
+using is_Handler = std::integral_constant<bool,
+    std::is_copy_constructible<std::decay_t<T>>::value &&
+        is_call_possible<T, Signature>::value>;
+
+#endif
+
+} // beast
+
+#endif

beast/http/tests/chunked_encoder.test.cpp

@@ -23,6 +23,7 @@
 
 namespace beast {
 namespace http {
+namespace test {
 
 class chunk_encode_test : public unit_test::suite
 {
@@ -98,7 +99,7 @@ public:
     check (std::string const& in, std::string const& answer,
         bool final_chunk = true)
     {
-        asio::streambuf sb(3);
+        streambuf sb(3);
         sb << in;
         auto const out = streambuf_to_string (sb, final_chunk);
         if (! expect (out == answer))
@@ -108,7 +109,7 @@ public:
 
     void testStreambuf()
     {
-        asio::streambuf sb(3);
+        streambuf sb(3);
         std::string const s =
             "0123456789012345678901234567890123456789012345678901234567890123456789"
             "0123456789012345678901234567890123456789012345678901234567890123456789"
@@ -147,5 +148,7 @@ public:
 
 BEAST_DEFINE_TESTSUITE(chunk_encode,http,beast);
 
-}
-}
+} // test
+} // http
+} // beast
+

beast/unity/beast_asio_unity.cpp

@@ -17,12 +17,6 @@
 */
 //==============================================================================
 
-#if BEAST_INCLUDE_BEASTCONFIG
-#include <BeastConfig.h>
-#endif
-
-#include <beast/asio/impl/error.cpp>
-#include <beast/asio/tests/bind_handler.test.cpp>
-#include <beast/asio/tests/streambuf.test.cpp>
-#include <beast/asio/tests/error_test.cpp>
-
+#include <beast/asio/src/test/beast_asio_bind_handler_test.cpp>
+#include <beast/asio/src/test/beast_asio_buffers_test.cpp>
+#include <beast/asio/src/test/beast_asio_error_test.cpp>

test/asio/Jamfile

@@ -0,0 +1,29 @@
+#
+# Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+#
+# Distributed under the Boost Software License, Version 1.0. (See accompanying
+# file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+#
+
+import os ;
+
+path-constant main : ../../beast/unit_test/src/main.cpp ;
+
+unit-test all :
+    append_buffers.cpp
+    asio.cpp
+    async_completion.cpp
+    basic_streambuf.cpp
+    bind_handler.cpp
+    buffers_adapter.cpp
+    buffers_debug.cpp
+    consuming_buffers.cpp
+    handler_alloc.cpp
+    placeholders.cpp
+    prepare_buffers.cpp
+    static_streambuf.cpp
+    streambuf.cpp
+    streambuf_readstream.cpp
+    type_check.cpp
+    $(main)
+    ;

test/asio/append_buffers.cpp

@@ -0,0 +1,76 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/append_buffers.h>
+
+#include <beast/unit_test/suite.h>
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/streambuf.hpp>
+#include <iterator>
+#include <list>
+#include <vector>
+
+namespace beast {
+namespace asio {
+namespace test {
+
+class append_buffers_test : public unit_test::suite
+{
+public:
+
+    void testAppendBuffers()
+    {
+        using boost::asio::buffer_size;
+        using boost::asio::const_buffer;
+        char buf[10];
+        std::list<const_buffer> b1;
+        std::vector<const_buffer> b2{
+            const_buffer{buf+0, 1},
+            const_buffer{buf+1, 2}};
+        std::list<const_buffer> b3;
+        std::array<const_buffer, 3> b4{{
+            const_buffer{buf+3, 1},
+            const_buffer{buf+4, 2},
+            const_buffer{buf+6, 3}}};
+        std::list<const_buffer> b5{
+            const_buffer{buf+9, 1}};
+        std::list<const_buffer> b6;
+        auto bs = append_buffers(
+            b1, b2, b3, b4, b5, b6);
+        expect(buffer_size(bs) == 10);
+        std::vector<const_buffer> v;
+        for(auto iter = std::make_reverse_iterator(bs.end());
+                iter != std::make_reverse_iterator(bs.begin()); ++iter)
+            v.emplace_back(*iter);
+        expect(buffer_size(bs) == 10);
+        decltype(bs) bs2(bs);
+        auto bs3(std::move(bs));
+        bs = bs2;
+        bs3 = std::move(bs2);
+        {
+            boost::asio::streambuf sb1, sb2;
+            expect(buffer_size(append_buffers(
+                sb1.prepare(5), sb2.prepare(7))) == 12);
+            sb1.commit(5);
+            sb2.commit(7);
+            expect(buffer_size(append_buffers(
+                sb1.data(), sb2.data())) == 12);
+        }
+    }
+
+    void run() override
+    {
+        testAppendBuffers();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(append_buffers,asio,beast);
+
+} // test
+} // asio
+} // beast

test/asio/asio.cpp

@@ -0,0 +1,9 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio.h>

test/asio/async_completion.cpp

@@ -0,0 +1,9 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/async_completion.h>

test/asio/basic_streambuf.cpp

@@ -0,0 +1,9 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/basic_streambuf.h>

test/asio/bind_handler.cpp

@@ -0,0 +1,11 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/bind_handler.h>
+
+#include <beast/asio/src/test/beast_asio_bind_handler_test.cpp>

test/asio/buffers_adapter.cpp

@@ -0,0 +1,124 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/buffers_adapter.h>
+
+#include <beast/unit_test/suite.h>
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/streambuf.hpp>
+#include <iterator>
+
+namespace beast {
+namespace asio {
+namespace test {
+
+class buffers_adapter_test : public unit_test::suite
+{
+public:
+    template<class ConstBufferSequence>
+    static
+    std::string
+    to_string(ConstBufferSequence const& bs)
+    {
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        std::string s;
+        s.reserve(buffer_size(bs));
+        for(auto const& b : bs)
+            s.append(buffer_cast<char const*>(b),
+                buffer_size(b));
+        return s;
+    }
+
+    void testBuffersAdapter()
+    {
+        using boost::asio::buffer;
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        using boost::asio::const_buffer;
+        using boost::asio::mutable_buffer;
+        char buf[12];
+        std::string const s = "Hello, world";
+        expect(s.size() == sizeof(buf));
+        for(std::size_t i = 1; i < 4; ++i) {
+        for(std::size_t j = 1; j < 4; ++j) {
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        for(std::size_t t = 1; t < 4; ++ t) {
+        for(std::size_t u = 1; u < 4; ++ u) {
+        std::size_t k = sizeof(buf) - (i + j);
+        std::size_t z = sizeof(buf) - (x + y);
+        std::size_t v = sizeof(buf) - (t + u);
+        {
+            std::memset(buf, 0, sizeof(buf));
+            std::array<mutable_buffer, 3> bs{{
+                mutable_buffer{&buf[0], i},
+                mutable_buffer{&buf[i], j},
+                mutable_buffer{&buf[i+j], k}}};
+            buffers_adapter<decltype(bs)> ba(std::move(bs));
+            expect(ba.max_size() == sizeof(buf));
+            decltype(ba)::mutable_buffers_type d;
+            d = ba.prepare(z); expect(buffer_size(d) == z);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            d = ba.prepare(y); expect(buffer_size(d) == y);
+            d = ba.prepare(x); expect(buffer_size(d) == x);
+            ba.commit(buffer_copy(d, buffer(s.data(), x)));
+            expect(ba.size() == x);
+            expect(ba.max_size() == sizeof(buf) - x);
+            expect(buffer_size(ba.data()) == ba.size());
+            d = ba.prepare(x); expect(buffer_size(d) == x);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            d = ba.prepare(z); expect(buffer_size(d) == z);
+            d = ba.prepare(y); expect(buffer_size(d) == y);
+            ba.commit(buffer_copy(d, buffer(s.data()+x, y)));
+            ba.commit(1);
+            expect(ba.size() == x + y);
+            expect(ba.max_size() == sizeof(buf) - (x + y));
+            expect(buffer_size(ba.data()) == ba.size());
+            d = ba.prepare(x); expect(buffer_size(d) == x);
+            d = ba.prepare(y); expect(buffer_size(d) == y);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            d = ba.prepare(z); expect(buffer_size(d) == z);
+            ba.commit(buffer_copy(d, buffer(s.data()+x+y, z)));
+            ba.commit(2);
+            expect(ba.size() == x + y + z);
+            expect(ba.max_size() == 0);
+            expect(buffer_size(ba.data()) == ba.size());
+            expect(to_string(ba.data()) == s);
+            ba.consume(t);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            expect(to_string(ba.data()) == s.substr(t, std::string::npos));
+            ba.consume(u);
+            expect(to_string(ba.data()) == s.substr(t + u, std::string::npos));
+            ba.consume(v);
+            expect(to_string(ba.data()) == "");
+            ba.consume(1);
+            d = ba.prepare(0); expect(buffer_size(d) == 0);
+            try
+            {
+                ba.prepare(1);
+                fail();
+            }
+            catch(...)
+            {
+                pass();
+            }
+        }
+        }}}}}}
+    }
+    void run() override
+    {
+        testBuffersAdapter();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(buffers_adapter,asio,beast);
+
+} // test
+} // asio
+} // beast

test/asio/buffers_debug.cpp

@@ -0,0 +1,9 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/buffers_debug.h>

test/asio/consuming_buffers.cpp

@@ -0,0 +1,97 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/consuming_buffers.h>
+
+#include <beast/unit_test/suite.h>
+#include <boost/asio/buffer.hpp>
+#include <string>
+
+namespace beast {
+namespace asio {
+namespace test {
+
+class consuming_buffers_test : public unit_test::suite
+{
+public:
+    template<class ConstBufferSequence>
+    static
+    std::string
+    to_string(ConstBufferSequence const& bs)
+    {
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        std::string s;
+        s.reserve(buffer_size(bs));
+        for(auto const& b : bs)
+            s.append(buffer_cast<char const*>(b),
+                buffer_size(b));
+        return s;
+    }
+
+    void testBuffers()
+    {
+        using boost::asio::buffer;
+        using boost::asio::const_buffer;
+        char buf[12];
+        std::string const s = "Hello, world";
+        expect(s.size() == sizeof(buf));
+        buffer_copy(buffer(buf), buffer(s));
+        expect(to_string(buffer(buf)) == s);
+        for(std::size_t i = 1; i < 4; ++i) {
+        for(std::size_t j = 1; j < 4; ++j) {
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        std::size_t k = sizeof(buf) - (i + j);
+        std::size_t z = sizeof(buf) - (x + y);
+        {
+            std::array<const_buffer, 3> bs{{
+                const_buffer{&buf[0], i},
+                const_buffer{&buf[i], j},
+                const_buffer{&buf[i+j], k}}};
+            consuming_buffers<decltype(bs)> cb(bs);
+            expect(to_string(cb) == s);
+            cb.consume(0);
+            expect(to_string(cb) == s);
+            cb.consume(x);
+            expect(to_string(cb) == s.substr(x));
+            cb.consume(y);
+            expect(to_string(cb) == s.substr(x+y));
+            cb.consume(z);
+            expect(to_string(cb) == "");
+            cb.consume(1);
+            expect(to_string(cb) == "");
+        }
+        }}}}
+    }
+
+    void testNullBuffers()
+    {
+        using boost::asio::buffer_copy;
+        using boost::asio::buffer_size;
+        using boost::asio::null_buffers;
+        consuming_buffers<null_buffers> cb(
+            null_buffers{});
+        expect(buffer_size(cb) == 0);
+        consuming_buffers<null_buffers> cb2(
+            null_buffers{});
+        expect(buffer_copy(cb2, cb) == 0);
+    }
+
+    void run() override
+    {
+        testBuffers();
+        testNullBuffers();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(consuming_buffers,asio,beast);
+
+} // test
+} // asio
+} // beast

test/asio/handler_alloc.cpp

@@ -0,0 +1,9 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/handler_alloc.h>

test/asio/placeholders.cpp

@@ -0,0 +1,9 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/placeholders.h>

test/asio/prepare_buffers.cpp

@@ -0,0 +1,103 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/prepare_buffers.h>
+
+#include <beast/asio/consuming_buffers.h>
+#include <beast/unit_test/suite.h>
+#include <boost/asio/buffer.hpp>
+#include <string>
+
+namespace beast {
+namespace asio {
+namespace test {
+
+class prepare_buffers_test : public unit_test::suite
+{
+public:
+    template<class ConstBufferSequence>
+    static
+    std::string
+    to_string(ConstBufferSequence const& bs)
+    {
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        std::string s;
+        s.reserve(buffer_size(bs));
+        for(auto const& b : bs)
+            s.append(buffer_cast<char const*>(b),
+                buffer_size(b));
+        return s;
+    }
+
+    void testBuffers()
+    {
+        using boost::asio::buffer_size;
+        using boost::asio::const_buffer;
+        std::string const s = "Hello, world";
+        expect(s.size() == 12);
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        std::size_t z = s.size() - (x + y);
+        {
+            std::array<const_buffer, 3> bs{{
+                const_buffer{&s[0], x},
+                const_buffer{&s[x], y},
+                const_buffer{&s[x+y], z}}};
+            for(std::size_t i = 0; i <= s.size() + 1; ++i)
+            {
+                auto pb = prepare_buffers(i, bs);
+                expect(to_string(pb) == s.substr(0, i));
+                auto pb2 = pb;
+                expect(to_string(pb2) == to_string(pb));
+                pb = prepare_buffers(0, bs);
+                pb2 = pb;
+                expect(buffer_size(pb2) == 0);
+                pb2 = prepare_buffers(i, bs);
+                expect(to_string(pb2) == s.substr(0, i));
+            }
+        }
+        }}
+    }
+
+    void testNullBuffers()
+    {
+        using boost::asio::buffer_copy;
+        using boost::asio::buffer_size;
+        using boost::asio::null_buffers;
+        auto pb0 = prepare_buffers(0, null_buffers{});
+        expect(buffer_size(pb0) == 0);
+        auto pb1 = prepare_buffers(1, null_buffers{});
+        expect(buffer_size(pb1) == 0);
+        expect(buffer_copy(pb0, pb1) == 0);
+
+        using pb_type = decltype(pb0);
+        consuming_buffers<pb_type> cb(pb0);
+        expect(buffer_size(cb) == 0);
+        expect(buffer_copy(cb, pb1) == 0);
+        cb.consume(1);
+        expect(buffer_size(cb) == 0);
+        expect(buffer_copy(cb, pb1) == 0);
+        
+        auto pbc = prepare_buffers(2, cb);
+        expect(buffer_size(pbc) == 0);
+        expect(buffer_copy(pbc, cb) == 0);
+    }
+
+    void run() override
+    {
+        testBuffers();
+        testNullBuffers();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(prepare_buffers,asio,beast);
+
+} // test
+} // asio
+} // beast

test/asio/static_streambuf.cpp

@@ -1,29 +1,22 @@
-//------------------------------------------------------------------------------
-/*
-    This file is part of Beast: https://github.com/vinniefalco/Beast
-    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
 
-    Permission to use, copy, modify, and/or distribute this software for any
-    purpose  with  or without fee is hereby granted, provided that the above
-    copyright notice and this permission notice appear in all copies.
+// Test that header file is self-contained.
+#include <beast/asio/static_streambuf.h>
 
-    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
-    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
-    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-//==============================================================================
-
-#include <beast/asio/streambuf.h>
 #include <beast/unit_test/suite.h>
+#include <boost/asio/buffer.hpp>
+#include <string>
 
 namespace beast {
 namespace asio {
+namespace test {
 
-class streambuf_test : public unit_test::suite
+class static_streambuf_test : public unit_test::suite
 {
 public:
     template<class ConstBufferSequence>
@@ -31,7 +24,8 @@ public:
     std::string
     to_string(ConstBufferSequence const& bs)
     {
-        using namespace boost::asio;
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
         std::string s;
         s.reserve(buffer_size(bs));
         for(auto const& b : bs)
@@ -40,13 +34,16 @@ public:
         return s;
     }
 
-    void testStreambuf()
+    void testStaticStreambuf()
     {
-        using namespace boost::asio;
+        using boost::asio::buffer;
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
         char buf[12];
         std::string const s = "Hello, world";
         expect(s.size() == sizeof(buf));
-        for(std::size_t i = 1; i < 12; ++i) {
+        for(std::size_t i = 1; i < 4; ++i) {
+        for(std::size_t j = 1; j < 4; ++j) {
         for(std::size_t x = 1; x < 4; ++x) {
         for(std::size_t y = 1; y < 4; ++y) {
         for(std::size_t t = 1; t < 4; ++ t) {
@@ -55,7 +52,7 @@ public:
         std::size_t v = sizeof(buf) - (t + u);
         {
             std::memset(buf, 0, sizeof(buf));
-            streambuf ba(i);
+            static_streambuf_n<sizeof(buf)> ba;
             decltype(ba)::mutable_buffers_type d;
             d = ba.prepare(z); expect(buffer_size(d) == z);
             d = ba.prepare(0); expect(buffer_size(d) == 0);
@@ -90,17 +87,27 @@ public:
             expect(to_string(ba.data()) == "");
             ba.consume(1);
             d = ba.prepare(0); expect(buffer_size(d) == 0);
+            try
+            {
+                ba.prepare(1);
+                fail();
             }
-        }}}}}
+            catch(...)
+            {
+                pass();
+            }
+        }
+        }}}}}}
     }
 
-    void run()
+    void run() override
     {
-        testStreambuf();
+        testStaticStreambuf();
     }
 };
 
-BEAST_DEFINE_TESTSUITE(streambuf,asio,beast);
+BEAST_DEFINE_TESTSUITE(static_streambuf,asio,beast);
 
-}
-}
+} // test
+} // asio
+} // beast

test/asio/streambuf.cpp

@@ -0,0 +1,296 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/streambuf.h>
+
+#include <beast/unit_test/suite.h>
+#include <boost/asio/buffer.hpp>
+#include <atomic>
+#include <memory>
+#include <string>
+
+namespace beast {
+namespace asio {
+namespace test {
+
+struct test_allocator_info
+{
+    std::size_t ncopy = 0;
+    std::size_t nmove = 0;
+    std::size_t nselect = 0;
+};
+
+template<class T,
+    bool Assign, bool Move, bool Swap, bool Select>
+class test_allocator;
+
+template<class T,
+    bool Assign, bool Move, bool Swap, bool Select>
+struct test_allocator_base
+{
+};
+
+template<class T,
+    bool Assign, bool Move, bool Swap>
+struct test_allocator_base<T, Assign, Move, Swap, true>
+{
+    static
+    test_allocator<T, Assign, Move, Swap, true>
+    select_on_container_copy_construction(
+        test_allocator<T, Assign, Move, Swap, true> const& a)
+    {
+        return test_allocator<T, Assign, Move, Swap, true>{};
+    }
+};
+
+template<class T,
+    bool Assign, bool Move, bool Swap, bool Select>
+class test_allocator : public test_allocator_base<
+        T, Assign, Move, Swap, Select>
+{
+    std::size_t id_;
+    std::shared_ptr<test_allocator_info> info_;
+
+    template<class, bool, bool, bool, bool>
+    friend class test_allocator;
+
+public:
+    using value_type = T;
+    using propagate_on_container_copy_assignment =
+        std::integral_constant<bool, Assign>;
+    using propagate_on_container_move_assignment =
+        std::integral_constant<bool, Move>;
+    using propagate_on_container_swap =
+        std::integral_constant<bool, Swap>;
+  
+    template<class U>
+    struct rebind
+    {
+        using other = test_allocator<
+            U, Assign, Move, Swap, Select>;
+    };
+
+    test_allocator()
+        : id_([]
+            {
+                static std::atomic<
+                    std::size_t> sid(0);
+                return ++sid;
+            }())
+        , info_(std::make_shared<test_allocator_info>())
+    {
+    }
+
+    test_allocator(test_allocator const& u) noexcept
+        : id_(u.id_)
+        , info_(u.info_)
+    {
+        ++info_->ncopy;
+    }
+
+    template<class U>
+    test_allocator(test_allocator<
+            U, Assign, Move, Swap, Select> const& u) noexcept
+        : id_(u.id_)
+        , info_(u.info_)
+    {
+        ++info_->ncopy;
+    }
+
+    test_allocator(test_allocator&& t)
+        : id_(t.id_)
+        , info_(t.info_)
+    {
+        ++info_->nmove;
+    }
+
+    value_type*
+    allocate(std::size_t n)
+    {
+        return static_cast<value_type*>(
+            ::operator new (n*sizeof(value_type)));
+    }
+
+    void
+    deallocate(value_type* p, std::size_t) noexcept
+    {
+        ::operator delete(p);
+    }
+
+    std::size_t 
+    id() const
+    {
+        return id_;
+    }
+
+    test_allocator_info const*
+    operator->() const
+    {
+        return info_.get();
+    }
+};
+
+class streambuf_test : public unit_test::suite
+{
+public:
+    template<class ConstBufferSequence>
+    static
+    std::string
+    to_string(ConstBufferSequence const& bs)
+    {
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        std::string s;
+        s.reserve(buffer_size(bs));
+        for(auto const& b : bs)
+            s.append(buffer_cast<char const*>(b),
+                buffer_size(b));
+        return s;
+    }
+
+    void testStreambuf()
+    {
+        using boost::asio::buffer;
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        std::string const s = "Hello, world";
+        expect(s.size() == 12);
+        for(std::size_t i = 1; i < 12; ++i) {
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        for(std::size_t t = 1; t < 4; ++ t) {
+        for(std::size_t u = 1; u < 4; ++ u) {
+        std::size_t z = s.size() - (x + y);
+        std::size_t v = s.size() - (t + u);
+        {
+            streambuf sb(i);
+            decltype(sb)::mutable_buffers_type d;
+            d = sb.prepare(z); expect(buffer_size(d) == z);
+            d = sb.prepare(0); expect(buffer_size(d) == 0);
+            d = sb.prepare(y); expect(buffer_size(d) == y);
+            d = sb.prepare(x); expect(buffer_size(d) == x);
+            sb.commit(buffer_copy(d, buffer(s.data(), x)));
+            expect(sb.size() == x);
+            expect(buffer_size(sb.data()) == sb.size());
+            d = sb.prepare(x); expect(buffer_size(d) == x);
+            d = sb.prepare(0); expect(buffer_size(d) == 0);
+            d = sb.prepare(z); expect(buffer_size(d) == z);
+            d = sb.prepare(y); expect(buffer_size(d) == y);
+            sb.commit(buffer_copy(d, buffer(s.data()+x, y)));
+            sb.commit(1);
+            expect(sb.size() == x + y);
+            expect(buffer_size(sb.data()) == sb.size());
+            d = sb.prepare(x); expect(buffer_size(d) == x);
+            d = sb.prepare(y); expect(buffer_size(d) == y);
+            d = sb.prepare(0); expect(buffer_size(d) == 0);
+            d = sb.prepare(z); expect(buffer_size(d) == z);
+            sb.commit(buffer_copy(d, buffer(s.data()+x+y, z)));
+            sb.commit(2);
+            expect(sb.size() == x + y + z);
+            expect(buffer_size(sb.data()) == sb.size());
+            expect(to_string(sb.data()) == s);
+            sb.consume(t);
+            d = sb.prepare(0); expect(buffer_size(d) == 0);
+            expect(to_string(sb.data()) == s.substr(t, std::string::npos));
+            sb.consume(u);
+            expect(to_string(sb.data()) == s.substr(t + u, std::string::npos));
+            sb.consume(v);
+            expect(to_string(sb.data()) == "");
+            sb.consume(1);
+            d = sb.prepare(0); expect(buffer_size(d) == 0);
+        }
+        }}}}}
+    }
+
+    template<class Alloc1, class Alloc2>
+    static
+    bool
+    eq(basic_streambuf<Alloc1> const& sb1,
+        basic_streambuf<Alloc2> const& sb2)
+    {
+        return to_string(sb1.data()) == to_string(sb2.data());
+    }
+
+    void testSpecial()
+    {
+        using boost::asio::buffer;
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        std::string const s = "Hello, world";
+        expect(s.size() == 12);
+        for(std::size_t i = 1; i < 12; ++i) {
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        std::size_t z = s.size() - (x + y);
+        {
+            streambuf sb(i);
+            sb.commit(buffer_copy(sb.prepare(x), buffer(s.data(), x)));
+            sb.commit(buffer_copy(sb.prepare(y), buffer(s.data()+x, y)));
+            sb.commit(buffer_copy(sb.prepare(z), buffer(s.data()+x+y, z)));
+            expect(to_string(sb.data()) == s);
+            {
+                streambuf sb2(sb);
+                expect(eq(sb, sb2));
+            }
+            {
+                streambuf sb2;
+                sb2 = sb;
+                expect(eq(sb, sb2));
+            }
+            {
+                streambuf sb2(std::move(sb));
+                expect(to_string(sb2.data()) == s);
+                expect(buffer_size(sb.data()) == 0);
+                sb = std::move(sb2);
+                expect(to_string(sb.data()) == s);
+                expect(buffer_size(sb2.data()) == 0);
+            }
+        }
+        }}}
+    }
+
+    void testAllocator()
+    {
+        {
+            using alloc_type =
+                test_allocator<char, false, false, false, false>;
+            using sb_type = basic_streambuf<alloc_type>;
+            sb_type sb;
+            expect(sb.get_allocator().id() == 1);
+        }
+        {
+            using alloc_type =
+                test_allocator<char, false, false, false, false>;
+            using sb_type = basic_streambuf<alloc_type>;
+            sb_type sb;
+            expect(sb.get_allocator().id() == 2);
+            sb_type sb2(sb);
+            expect(sb2.get_allocator().id() == 2);
+            sb_type sb3(sb, alloc_type{});
+            //expect(sb3.get_allocator().id() == 3);
+        }
+        {
+            using alloc_type =
+                test_allocator<char, false, false, false, false>;
+            using sb_type = basic_streambuf<alloc_type>;
+        }
+    }
+
+    void run() override
+    {
+        testStreambuf();
+        testSpecial();
+        testAllocator();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(streambuf,asio,beast);
+
+} // test
+} // asio
+} // beast

test/asio/streambuf_readstream.cpp

@@ -0,0 +1,9 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/streambuf_readstream.h>

test/asio/temp_buffer.cpp

@@ -0,0 +1,9 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/temp_buffer.h>

test/asio/type_check.cpp

@@ -0,0 +1,9 @@
+//
+// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/asio/type_check.h>