1 files changed, 98 insertions, 0 deletions
diff --git a/boost/beast/core/detail/buffer_traits.hpp b/boost/beast/core/detail/buffer_traits.hpp
new file mode 100644
index 0000000000..a50aa5d80d
--- /dev/null
+++ b/boost/beast/core/detail/buffer_traits.hpp
@@ -0,0 +1,98 @@
+//
+// Copyright (c) 2016-2019 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)
+//
+// Official repository: https://github.com/boostorg/beast
+//
+
+#ifndef BOOST_BEAST_DETAIL_BUFFER_TRAITS_HPP
+#define BOOST_BEAST_DETAIL_BUFFER_TRAITS_HPP
+
+#include <boost/asio/buffer.hpp>
+#include <boost/config/workaround.hpp>
+#include <boost/type_traits/make_void.hpp>
+#include <cstdint>
+#include <type_traits>
+
+namespace boost {
+namespace beast {
+namespace detail {
+
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1910)
+
+template<class T>
+struct buffers_iterator_type_helper
+{
+    using type = decltype(
+        net::buffer_sequence_begin(
+            std::declval<T const&>()));
+};
+
+template<>
+struct buffers_iterator_type_helper<
+    net::const_buffer>
+{
+    using type = net::const_buffer const*;
+};
+
+template<>
+struct buffers_iterator_type_helper<
+    net::mutable_buffer>
+{
+    using type = net::mutable_buffer const*;
+};
+
+#endif
+
+struct buffer_bytes_impl
+{
+    std::size_t
+    operator()(net::const_buffer b) const noexcept
+    {
+        return net::const_buffer(b).size();
+    }
+
+    std::size_t
+    operator()(net::mutable_buffer b) const noexcept
+    {
+        return net::mutable_buffer(b).size();
+    }
+
+    template<
+        class B,
+        class = typename std::enable_if<
+            net::is_const_buffer_sequence<B>::value>::type>
+    std::size_t
+    operator()(B const& b) const noexcept
+    {
+        using net::buffer_size;
+        return buffer_size(b);
+    }
+};
+
+/** Return `true` if a buffer sequence is empty
+
+    This is sometimes faster than using @ref buffer_bytes
+*/
+template<class ConstBufferSequence>
+bool
+buffers_empty(ConstBufferSequence const& buffers)
+{
+    auto it = net::buffer_sequence_begin(buffers);
+    auto end = net::buffer_sequence_end(buffers);
+    while(it != end)
+    {
+        if(net::const_buffer(*it).size() > 0)
+            return false;
+        ++it;
+    }
+    return true;
+}
+
+} // detail
+} // beast
+} // boost
+
+#endif