ceph/src/boost/boost/beast/core/ostream.hpp

   1 //
   2 // Copyright (c) 2016-2017 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_WRITE_OSTREAM_HPP
  11 #define BOOST_BEAST_WRITE_OSTREAM_HPP
  12
  13 #include <boost/beast/core/detail/config.hpp>
  14 #include <boost/beast/core/type_traits.hpp>
  15 #include <boost/beast/core/detail/ostream.hpp>
  16 #include <type_traits>
  17 #include <streambuf>
  18 #include <utility>
  19
  20 namespace boost {
  21 namespace beast {
  22
  23 /** Return an object representing a @b ConstBufferSequence.
  24
  25     This function wraps a reference to a buffer sequence and permits
  26     the following operation:
  27
  28     @li `operator<<` to `std::ostream`. No character translation is
  29         performed; unprintable and null characters will be transferred
  30         as-is to the output stream.
  31
  32     @par Example
  33     @code
  34         multi_buffer b;
  35         ...
  36         std::cout << buffers(b.data()) << std::endl;
  37     @endcode
  38
  39     @param b An object meeting the requirements of @b ConstBufferSequence
  40     to be streamed. The implementation will make a copy of this object.
  41     Ownership of the underlying memory is not transferred, the application
  42     is still responsible for managing its lifetime.
  43 */
  44 template<class ConstBufferSequence>
  45 #if BOOST_BEAST_DOXYGEN
  46 implementation_defined
  47 #else
  48 detail::buffers_helper<ConstBufferSequence>
  49 #endif
  50 buffers(ConstBufferSequence const& b)
  51 {
  52     static_assert(boost::asio::is_const_buffer_sequence<
  53         ConstBufferSequence>::value,
  54             "ConstBufferSequence requirements not met");
  55     return detail::buffers_helper<
  56         ConstBufferSequence>{b};
  57 }
  58
  59 /** Return an output stream that formats values into a @b DynamicBuffer.
  60
  61     This function wraps the caller provided @b DynamicBuffer into
  62     a `std::ostream` derived class, to allow `operator<<` stream style
  63     formatting operations.
  64
  65     @par Example
  66     @code
  67         ostream(buffer) << "Hello, world!" << std::endl;
  68     @endcode
  69
  70     @note Calling members of the underlying buffer before the output
  71     stream is destroyed results in undefined behavior.
  72
  73     @param buffer An object meeting the requirements of @b DynamicBuffer
  74     into which the formatted output will be placed.
  75
  76     @return An object derived from `std::ostream` which redirects output
  77     The wrapped dynamic buffer is not modified, a copy is made instead.
  78     Ownership of the underlying memory is not transferred, the application
  79     is still responsible for managing its lifetime. The caller is
  80     responsible for ensuring the dynamic buffer is not destroyed for the
  81     lifetime of the output stream.
  82 */
  83 template<class DynamicBuffer>
  84 #if BOOST_BEAST_DOXYGEN
  85 implementation_defined
  86 #else
  87 detail::ostream_helper<
  88     DynamicBuffer, char, std::char_traits<char>,
  89         detail::basic_streambuf_movable::value>
  90 #endif
  91 ostream(DynamicBuffer& buffer)
  92 {
  93     static_assert(
  94         boost::asio::is_dynamic_buffer<DynamicBuffer>::value,
  95         "DynamicBuffer requirements not met");
  96     return detail::ostream_helper<
  97         DynamicBuffer, char, std::char_traits<char>,
  98             detail::basic_streambuf_movable::value>{buffer};
  99 }
 100
 101 } // beast
 102 } // boost
 103
 104 #endif