1 // 2 // wait_traits.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_WAIT_TRAITS_HPP 12 #define BOOST_ASIO_WAIT_TRAITS_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/push_options.hpp> 19 20 namespace boost { 21 namespace asio { 22 23 /// Wait traits suitable for use with the basic_waitable_timer class template. 24 template <typename Clock> 25 struct wait_traits 26 { 27 /// Convert a clock duration into a duration used for waiting. 28 /** 29 * @returns @c d. 30 */ to_wait_durationboost::asio::wait_traits31 static typename Clock::duration to_wait_duration( 32 const typename Clock::duration& d) 33 { 34 return d; 35 } 36 37 /// Convert a clock duration into a duration used for waiting. 38 /** 39 * @returns @c d. 40 */ to_wait_durationboost::asio::wait_traits41 static typename Clock::duration to_wait_duration( 42 const typename Clock::time_point& t) 43 { 44 typename Clock::time_point now = Clock::now(); 45 if (now + (Clock::duration::max)() < t) 46 return (Clock::duration::max)(); 47 if (now + (Clock::duration::min)() > t) 48 return (Clock::duration::min)(); 49 return t - now; 50 } 51 }; 52 53 } // namespace asio 54 } // namespace boost 55 56 #include <boost/asio/detail/pop_options.hpp> 57 58 #endif // BOOST_ASIO_WAIT_TRAITS_HPP 59