core/detail/buffers_range_adaptor.hpp

0001 //
0002 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
0003 //
0004 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007 // Official repository: https://github.com/boostorg/beast
0008 //
0009
0010 #ifndef BOOST_BEAST_DETAIL_BUFFERS_RANGE_ADAPTOR_HPP
0011 #define BOOST_BEAST_DETAIL_BUFFERS_RANGE_ADAPTOR_HPP
0012
0013 #include <boost/beast/core/buffer_traits.hpp>
0014 #include <iterator>
0015 #include <type_traits>
0016
0017 namespace boost {
0018 namespace beast {
0019 namespace detail {
0020
0021 template<class BufferSequence>
0022 class buffers_range_adaptor
0023 {
0024     BufferSequence b_;
0025
0026 public:
0027 #if BOOST_BEAST_DOXYGEN
0028     using value_type = __see_below__;
0029 #else
0030     using value_type = buffers_type<BufferSequence>;
0031 #endif
0032
0033     class const_iterator
0034     {
0035         friend class buffers_range_adaptor;
0036
0037         using iter_type =
0038             buffers_iterator_type<BufferSequence>;
0039
0040         iter_type it_{};
0041
0042         const_iterator(iter_type const& it)
0043             : it_(it)
0044         {
0045         }
0046
0047     public:
0048         using value_type = typename
0049             buffers_range_adaptor::value_type;
0050         using pointer = value_type const*;
0051         using reference = value_type;
0052         using difference_type = std::ptrdiff_t;
0053         using iterator_category =
0054             std::bidirectional_iterator_tag;
0055
0056         const_iterator() = default;
0057
0058         bool
0059         operator==(const_iterator const& other) const
0060         {
0061             return it_ == other.it_;
0062         }
0063
0064         bool
0065         operator!=(const_iterator const& other) const
0066         {
0067             return !(*this == other);
0068         }
0069
0070         reference
0071         operator*() const
0072         {
0073             return *it_;
0074         }
0075
0076         pointer
0077         operator->() const = delete;
0078
0079         const_iterator&
0080         operator++()
0081         {
0082             ++it_;
0083             return *this;
0084         }
0085
0086         const_iterator
0087         operator++(int)
0088         {
0089             auto temp = *this;
0090             ++(*this);
0091             return temp;
0092         }
0093
0094         const_iterator&
0095         operator--()
0096         {
0097             --it_;
0098             return *this;
0099         }
0100
0101         const_iterator
0102         operator--(int)
0103         {
0104             auto temp = *this;
0105             --(*this);
0106             return temp;
0107         }
0108     };
0109
0110     explicit
0111     buffers_range_adaptor(BufferSequence const& b)
0112         : b_(b)
0113     {
0114     }
0115
0116     const_iterator
0117     begin() const noexcept
0118     {
0119         return {net::buffer_sequence_begin(b_)};
0120     }
0121
0122     const_iterator
0123     end() const noexcept
0124     {
0125         return {net::buffer_sequence_end(b_)};
0126     }
0127 };
0128
0129 } // detail
0130 } // beast
0131 } // boost
0132
0133 #endif