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.

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