1 // 2 // detail/future.hpp 3 // ~~~~~~~~~~~~~~~~~ 4 // 5 // Copyright (c) 2003-2021 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_DETAIL_FUTURE_HPP 12 #define BOOST_ASIO_DETAIL_FUTURE_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 #if defined(BOOST_ASIO_HAS_STD_FUTURE) 20 # include <future> 21 // Even though the future header is available, libstdc++ may not implement the 22 // std::future class itself. However, we need to have already included the 23 // future header to reliably test for _GLIBCXX_HAS_GTHREADS. 24 # if defined(__GNUC__) && !defined(BOOST_ASIO_HAS_CLANG_LIBCXX) 25 # if defined(_GLIBCXX_HAS_GTHREADS) 26 # define BOOST_ASIO_HAS_STD_FUTURE_CLASS 1 27 # endif // defined(_GLIBCXX_HAS_GTHREADS) 28 # else // defined(__GNUC__) && !defined(BOOST_ASIO_HAS_CLANG_LIBCXX) 29 # define BOOST_ASIO_HAS_STD_FUTURE_CLASS 1 30 # endif // defined(__GNUC__) && !defined(BOOST_ASIO_HAS_CLANG_LIBCXX) 31 #endif // defined(BOOST_ASIO_HAS_STD_FUTURE) 32 33 #endif // BOOST_ASIO_DETAIL_FUTURE_HPP 34