//
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// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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// Official repository: https://github.com/boostorg/beast
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//
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#ifndef BOOST_BEAST_BUFFER_TRAITS_HPP
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#define BOOST_BEAST_BUFFER_TRAITS_HPP
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#include <boost/beast/core/detail/config.hpp>
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#include <boost/beast/core/detail/buffer_traits.hpp>
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#include <boost/beast/core/detail/static_const.hpp>
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#include <boost/asio/buffer.hpp>
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#include <boost/config/workaround.hpp>
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#include <boost/mp11/function.hpp>
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#include <type_traits>
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namespace boost {
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namespace beast {
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/** Determine if a list of types satisfy the <em>ConstBufferSequence</em> requirements.
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This metafunction is used to determine if all of the specified types
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meet the requirements for constant buffer sequences. This type alias
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will be `std::true_type` if each specified type meets the requirements,
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otherwise, this type alias will be `std::false_type`.
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@tparam BufferSequence A list of zero or more types to check. If this
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list is empty, the resulting type alias will be `std::true_type`.
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*/
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template<class... BufferSequence>
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#if BOOST_BEAST_DOXYGEN
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using is_const_buffer_sequence = __see_below__;
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#else
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using is_const_buffer_sequence = mp11::mp_all<
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net::is_const_buffer_sequence<
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typename std::decay<BufferSequence>::type>...>;
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#endif
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/** Determine if a list of types satisfy the <em>MutableBufferSequence</em> requirements.
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This metafunction is used to determine if all of the specified types
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meet the requirements for mutable buffer sequences. This type alias
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will be `std::true_type` if each specified type meets the requirements,
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otherwise, this type alias will be `std::false_type`.
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@tparam BufferSequence A list of zero or more types to check. If this
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list is empty, the resulting type alias will be `std::true_type`.
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*/
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template<class... BufferSequence>
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#if BOOST_BEAST_DOXYGEN
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using is_mutable_buffer_sequence = __see_below__;
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#else
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using is_mutable_buffer_sequence = mp11::mp_all<
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net::is_mutable_buffer_sequence<
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typename std::decay<BufferSequence>::type>...>;
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#endif
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/** Type alias for the underlying buffer type of a list of buffer sequence types.
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This metafunction is used to determine the underlying buffer type for
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a list of buffer sequence. The equivalent type of the alias will vary
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depending on the template type argument:
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@li If every type in the list is a <em>MutableBufferSequence</em>,
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the resulting type alias will be `net::mutable_buffer`, otherwise
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@li The resulting type alias will be `net::const_buffer`.
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@par Example
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The following code returns the first buffer in a buffer sequence,
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or generates a compilation error if the argument is not a buffer
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sequence:
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@code
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template <class BufferSequence>
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buffers_type <BufferSequence>
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buffers_front (BufferSequence const& buffers)
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{
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static_assert(
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net::is_const_buffer_sequence<BufferSequence>::value,
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"BufferSequence type requirements not met");
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auto const first = net::buffer_sequence_begin (buffers);
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if (first == net::buffer_sequence_end (buffers))
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return {};
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return *first;
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}
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@endcode
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@tparam BufferSequence A list of zero or more types to check. If this
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list is empty, the resulting type alias will be `net::mutable_buffer`.
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*/
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template<class... BufferSequence>
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#if BOOST_BEAST_DOXYGEN
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using buffers_type = __see_below__;
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#else
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using buffers_type = typename std::conditional<
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is_mutable_buffer_sequence<BufferSequence...>::value,
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net::mutable_buffer, net::const_buffer>::type;
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#endif
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/** Type alias for the iterator type of a buffer sequence type.
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This metafunction is used to determine the type of iterator
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used by a particular buffer sequence.
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@tparam T The buffer sequence type to use. The resulting
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type alias will be equal to the iterator type used by
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the buffer sequence.
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*/
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template <class BufferSequence>
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#if BOOST_BEAST_DOXYGEN
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using buffers_iterator_type = __see_below__;
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#elif BOOST_WORKAROUND(BOOST_MSVC, < 1910)
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using buffers_iterator_type = typename
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detail::buffers_iterator_type_helper<
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typename std::decay<BufferSequence>::type>::type;
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#else
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using buffers_iterator_type =
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decltype(net::buffer_sequence_begin(
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std::declval<BufferSequence const&>()));
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#endif
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/** Return the total number of bytes in a buffer or buffer sequence
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This function returns the total number of bytes in a buffer,
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buffer sequence, or object convertible to a buffer. Specifically
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it may be passed:
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@li A <em>ConstBufferSequence</em> or <em>MutableBufferSequence</em>
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@li A `net::const_buffer` or `net::mutable_buffer`
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@li An object convertible to `net::const_buffer`
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This function is designed as an easier-to-use replacement for
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`net::buffer_size`. It recognizes customization points found through
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argument-dependent lookup. The call `beast::buffer_bytes(b)` is
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equivalent to performing:
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@code
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using net::buffer_size;
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return buffer_size(b);
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@endcode
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In addition this handles types which are convertible to
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`net::const_buffer`; these are not handled by `net::buffer_size`.
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@param buffers The buffer or buffer sequence to calculate the size of.
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@return The total number of bytes in the buffer or sequence.
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*/
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#if BOOST_BEAST_DOXYGEN
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template<class BufferSequence>
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std::size_t
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buffer_bytes(BufferSequence const& buffers);
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#else
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BOOST_BEAST_INLINE_VARIABLE(buffer_bytes, detail::buffer_bytes_impl)
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#endif
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} // beast
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} // boost
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#endif
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