Squashed 'src/beast/' changes from 1b9a714..6d5547a

6d5547a Set version to 1.0.0-b34
6fab138 Fix and tidy up CMake build scripts:
ccefa54 Set version to 1.0.0-b33
32afe41 Set internal state correctly when writing frames:
fe3e20b Add write_frames unit test
578dcd0 Add decorator unit test
aaa3733 Use fwrite return value in file_body
df66165 Require Visual Studio 2015 Update 3 or later
b8e5a21 Set version to 1.0.0-b32
ffb1758 Update CMake scripts for finding packages:
b893749 Remove http Writer suspend and resume feature (API Change):
27864fb Add io_service completion invariants tests
eba05a7 Set version to 1.0.0-b31
484bcef Fix badge markdown in README.md
5663bea Add missing dynabuf_readstream member
0d7a551 Tidy up build settings
0fd4030 Move the handler, don't copy it

git-subtree-dir: src/beast
git-subtree-split: 6d5547a32c50ec95832c4779311502555ab0ee1f

include/beast/core/handler_alloc.hpp

@@ -0,0 +1,141 @@
+//
+// Copyright (c) 2013-2017 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)
+//
+
+#ifndef BEAST_HANDLER_ALLOC_HPP
+#define BEAST_HANDLER_ALLOC_HPP
+
+#include <beast/config.hpp>
+#include <beast/core/handler_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. It meets the requirements
+    of @b Allocator and can be used anywhere a `std::allocator` is
+    accepted.
+
+    @tparam T The type of objects allocated by the allocator.
+
+    @tparam Handler The type of handler.
+
+    @note Memory allocated by this allocator must be freed before
+    the handler is invoked or undefined behavior results. This behavior
+    is described as the "deallocate before invocation" Asio guarantee.
+*/
+#if GENERATING_DOCS
+template<class T, class Handler>
+class handler_alloc;
+#else
+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;
+
+    template<class U>
+    struct rebind
+    {
+        using other = handler_alloc<U, Handler>;
+    };
+
+    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.
+
+        A reference of the handler is stored. The handler must
+        remain valid for at least the lifetime of the allocator.
+    */
+    explicit
+    handler_alloc(Handler& h)
+        : h_(h)
+    {
+    }
+
+    /// Copy constructor
+    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*>(
+            beast_asio_helpers::allocate(
+                size, h_));
+    }
+
+    void
+    deallocate(value_type* p, std::ptrdiff_t n)
+    {
+        auto const size = n * sizeof(T);
+        beast_asio_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);
+    }
+};
+#endif
+
+} // beast
+
+#endif