ceph/src/boost/boost/beast/core/detail/buffers_ref.hpp

   1 //
   2 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
   3 //
   4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // Official repository: https://github.com/boostorg/beast
   8 //
   9
  10 #ifndef BOOST_BEAST_DETAIL_BUFFERS_REF_HPP
  11 #define BOOST_BEAST_DETAIL_BUFFERS_REF_HPP
  12
  13 #include <boost/beast/core/buffer_traits.hpp>
  14 #include <iterator>
  15 #include <memory>
  16
  17 namespace boost {
  18 namespace beast {
  19 namespace detail {
  20
  21 // A very lightweight reference to a buffer sequence
  22 template<class BufferSequence>
  23 class buffers_ref
  24 {
  25     BufferSequence const* buffers_;
  26
  27 public:
  28     using const_iterator =
  29         buffers_iterator_type<BufferSequence>;
  30
  31     using value_type = typename
  32         std::iterator_traits<const_iterator>::value_type;
  33
  34     buffers_ref(buffers_ref const&) = default;
  35     buffers_ref& operator=(buffers_ref const&) = default;
  36
  37     explicit
  38     buffers_ref(BufferSequence const& buffers)
  39         : buffers_(std::addressof(buffers))
  40     {
  41     }
  42
  43     const_iterator
  44     begin() const
  45     {
  46         return net::buffer_sequence_begin(*buffers_);
  47     }
  48
  49     const_iterator
  50     end() const
  51     {
  52         return net::buffer_sequence_end(*buffers_);
  53     }
  54 };
  55
  56 // Return a reference to a buffer sequence
  57 template<class BufferSequence>
  58 buffers_ref<BufferSequence>
  59 make_buffers_ref(BufferSequence const& buffers)
  60 {
  61     static_assert(
  62         is_const_buffer_sequence<BufferSequence>::value,
  63         "BufferSequence type requirements not met");
  64     return buffers_ref<BufferSequence>(buffers);
  65 }
  66
  67 } // detail
  68 } // beast
  69 } // boost
  70
  71 #endif