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