1 // 2 // placeholders.hpp 3 // ~~~~~~~~~~~~~~~~ 4 // 5 // Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com) 6 // 7 // Distributed under the Boost Software License, Version 1.0. (See accompanying 8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 9 // 10 11 #ifndef BOOST_ASIO_PLACEHOLDERS_HPP 12 #define BOOST_ASIO_PLACEHOLDERS_HPP 13 14 #if defined(_MSC_VER) && (_MSC_VER >= 1200) 15 # pragma once 16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) 17 18 #include <boost/asio/detail/config.hpp> 19 20 #if defined(BOOST_ASIO_HAS_BOOST_BIND) 21 # include <boost/bind/arg.hpp> 22 #endif // defined(BOOST_ASIO_HAS_BOOST_BIND) 23 24 #include <boost/asio/detail/push_options.hpp> 25 26 namespace boost { 27 namespace asio { 28 namespace placeholders { 29 30 #if defined(GENERATING_DOCUMENTATION) 31 32 /// An argument placeholder, for use with boost::bind(), that corresponds to 33 /// the error argument of a handler for any of the asynchronous functions. 34 unspecified error; 35 36 /// An argument placeholder, for use with boost::bind(), that corresponds to 37 /// the bytes_transferred argument of a handler for asynchronous functions such 38 /// as boost::asio::basic_stream_socket::async_write_some or 39 /// boost::asio::async_write. 40 unspecified bytes_transferred; 41 42 /// An argument placeholder, for use with boost::bind(), that corresponds to 43 /// the iterator argument of a handler for asynchronous functions such as 44 /// boost::asio::basic_resolver::async_resolve. 45 unspecified iterator; 46 47 /// An argument placeholder, for use with boost::bind(), that corresponds to 48 /// the signal_number argument of a handler for asynchronous functions such as 49 /// boost::asio::signal_set::async_wait. 50 unspecified signal_number; 51 52 #elif defined(BOOST_ASIO_HAS_BOOST_BIND) 53 # if defined(__BORLANDC__) || defined(__GNUC__) 54 55 inline boost::arg<1> error() 56 { 57 return boost::arg<1>(); 58 } 59 60 inline boost::arg<2> bytes_transferred() 61 { 62 return boost::arg<2>(); 63 } 64 65 inline boost::arg<2> iterator() 66 { 67 return boost::arg<2>(); 68 } 69 70 inline boost::arg<2> signal_number() 71 { 72 return boost::arg<2>(); 73 } 74 75 # else 76 77 namespace detail 78 { 79 template <int Number> 80 struct placeholder 81 { 82 static boost::arg<Number>& get() 83 { 84 static boost::arg<Number> result; 85 return result; 86 } 87 }; 88 } 89 90 # if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC < 1400) 91 92 static boost::arg<1>& error 93 = boost::asio::placeholders::detail::placeholder<1>::get(); 94 static boost::arg<2>& bytes_transferred 95 = boost::asio::placeholders::detail::placeholder<2>::get(); 96 static boost::arg<2>& iterator 97 = boost::asio::placeholders::detail::placeholder<2>::get(); 98 static boost::arg<2>& signal_number 99 = boost::asio::placeholders::detail::placeholder<2>::get(); 100 101 # else 102 103 namespace 104 { 105 boost::arg<1>& error 106 = boost::asio::placeholders::detail::placeholder<1>::get(); 107 boost::arg<2>& bytes_transferred 108 = boost::asio::placeholders::detail::placeholder<2>::get(); 109 boost::arg<2>& iterator 110 = boost::asio::placeholders::detail::placeholder<2>::get(); 111 boost::arg<2>& signal_number 112 = boost::asio::placeholders::detail::placeholder<2>::get(); 113 } // namespace 114 115 # endif 116 # endif 117 #endif 118 119 } // namespace placeholders 120 } // namespace asio 121 } // namespace boost 122 123 #include <boost/asio/detail/pop_options.hpp> 124 125 #endif // BOOST_ASIO_PLACEHOLDERS_HPP 126