Refactor beast::asio:

* New tools for completion handlers:
  - wrap_handler provides composed io_service execution guarantees.
  - bind_handler rebinds arguments to handlers.
  - shared_handler type-erases any completion handler.
  - buffer_sequence type-erases templated BufferSequences
  - abstract_socket replaces Socket
  - socket_wrapper replaces SocketWrapper
  - beast::asio placeholders to work with std::bind

* Removed obsolete classes and functions
  - AbstractHandler
  - ComposedAsyncOperation
  - SharedFunction
  - SharedHandler
  - SharedHandlerAllocator
  - SharedHandlerPtr
  - SharedHandlerType
  - SocketBase
  - SocketWrapperStrand
  - wrapHandler

* Refactored classes to use new tools
  - abstract_socket
  - socket_wrapper
  - HandshakeDetector
  - HttpClientType

* Miscellanous tidying
  - socket classes moved to beast::asio namespace
  - beast asio files provide their own namespace declaration.
  - Fix IsCallPossible conflicting template parameter name
  - Use <boost/get_pointer.hpp> for C++11 compatibility.
  - Remove extraneous include path from build environment.

beast/asio/abstract_socket.cpp

@@ -0,0 +1,217 @@
+//------------------------------------------------------------------------------
+/*
+    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 "abstract_socket.h"
+#include "bind_handler.h"
+
+namespace beast {
+namespace asio {
+
+#if ! BEAST_COMPILER_CHECKS_SOCKET_OVERRIDES
+
+//------------------------------------------------------------------------------
+//
+// Socket
+//
+//------------------------------------------------------------------------------
+
+void* abstract_socket::this_layer_ptr (char const*) const
+{
+    pure_virtual_called ();
+    return nullptr;
+}
+
+//------------------------------------------------------------------------------
+//
+// native_handle
+//
+//------------------------------------------------------------------------------
+
+bool abstract_socket::native_handle (char const*, void*)
+{
+    pure_virtual_called ();
+    return false;
+}
+
+//------------------------------------------------------------------------------
+//
+// basic_io_object
+//
+//------------------------------------------------------------------------------
+
+boost::asio::io_service& abstract_socket::get_io_service ()
+{
+    pure_virtual_called ();
+    return *static_cast <boost::asio::io_service*>(nullptr);
+}
+
+//------------------------------------------------------------------------------
+//
+// basic_socket
+//
+//------------------------------------------------------------------------------
+
+void*
+abstract_socket::lowest_layer_ptr (char const*) const
+{
+    pure_virtual_called ();
+    return nullptr;
+}
+
+auto
+abstract_socket::cancel (boost::system::error_code& ec) -> error_code
+{
+    return pure_virtual_error (ec);
+}
+
+auto
+abstract_socket::shutdown (shutdown_type, boost::system::error_code& ec) -> error_code
+{
+    return pure_virtual_error (ec);
+}
+
+auto
+abstract_socket::close (boost::system::error_code& ec) -> error_code
+{
+    return pure_virtual_error (ec);
+}
+
+//------------------------------------------------------------------------------
+//
+// basic_socket_acceptor
+//
+//------------------------------------------------------------------------------
+
+auto 
+abstract_socket::accept (abstract_socket&, error_code& ec) -> error_code
+{
+    return pure_virtual_error (ec);
+}
+
+void
+abstract_socket::async_accept (abstract_socket&, error_handler handler)
+{
+    get_io_service ().post (bind_handler (
+        handler, pure_virtual_error()));
+}
+
+//------------------------------------------------------------------------------
+//
+// basic_stream_socket
+//
+//------------------------------------------------------------------------------
+
+std::size_t
+abstract_socket::read_some (mutable_buffers, error_code& ec)
+{
+    ec = pure_virtual_error ();
+    return 0;
+}
+
+std::size_t
+abstract_socket::write_some (const_buffers, error_code& ec)
+{
+    ec = pure_virtual_error ();
+    return 0;
+}
+
+void
+abstract_socket::async_read_some (mutable_buffers, transfer_handler handler)
+{
+    get_io_service ().post (bind_handler (
+        handler, pure_virtual_error(), 0));
+}
+
+void
+abstract_socket::async_write_some (const_buffers, transfer_handler handler)
+{
+    get_io_service ().post (bind_handler (
+        handler, pure_virtual_error(), 0));
+}
+
+//------------------------------------------------------------------------------
+//
+// ssl::stream
+//
+//------------------------------------------------------------------------------
+
+void*
+abstract_socket::next_layer_ptr (char const*) const
+{
+    pure_virtual_called ();
+    return nullptr;
+}
+
+bool
+abstract_socket::needs_handshake ()
+{
+    return false;
+}
+
+void
+abstract_socket::set_verify_mode (int)
+{
+    pure_virtual_called ();
+}
+
+auto
+abstract_socket::handshake (handshake_type, error_code& ec) -> error_code
+{
+    return pure_virtual_error (ec);
+}
+
+void
+abstract_socket::async_handshake (handshake_type, error_handler handler)
+{
+    get_io_service ().post (bind_handler (
+        handler, pure_virtual_error()));
+}
+
+auto
+abstract_socket::handshake (handshake_type, const_buffers, error_code& ec) ->
+    error_code
+{
+    return pure_virtual_error (ec);
+}
+
+void
+abstract_socket::async_handshake (handshake_type, const_buffers,
+    transfer_handler handler)
+{
+    get_io_service ().post (bind_handler (
+        handler, pure_virtual_error(), 0));
+}
+
+auto
+abstract_socket::shutdown (error_code& ec) -> error_code
+{
+    return pure_virtual_error (ec);
+}
+
+void
+abstract_socket::async_shutdown (error_handler handler)
+{
+    get_io_service ().post (bind_handler (
+        handler, pure_virtual_error()));
+}
+
+#endif
+
+}
+}