ceph/src/boost/libs/fiber/include/boost/fiber/future/async.hpp

   1
   2 //          Copyright Oliver Kowalke 2013.
   3 // Distributed under the Boost Software License, Version 1.0.
   4 //    (See accompanying file LICENSE_1_0.txt or copy at
   5 //          http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #ifndef BOOST_FIBERS_ASYNC_HPP
   8 #define BOOST_FIBERS_ASYNC_HPP
   9
  10 #include <algorithm>
  11 #include <memory>
  12 #include <type_traits>
  13 #include <utility>
  14
  15 #include <boost/config.hpp>
  16
  17 #include <boost/fiber/future/future.hpp>
  18 #include <boost/fiber/future/packaged_task.hpp>
  19 #include <boost/fiber/policy.hpp>
  20
  21 namespace boost {
  22 namespace fibers {
  23
  24 template< typename Fn, typename ... Args >
  25 future<
  26         typename std::result_of<
  27                 typename std::enable_if<
  28                         ! detail::is_launch_policy< typename std::decay< Fn >::type >::value,
  29                         typename std::decay< Fn >::type
  30                 >::type( typename std::decay< Args >::type ... )
  31         >::type
  32 >
  33 async( Fn && fn, Args && ... args) {
  34     typedef typename std::result_of<
  35         typename std::decay< Fn >::type( typename std::decay< Args >::type ... )
  36     >::type     result_t;
  37
  38     packaged_task< result_t( typename std::decay< Args >::type ... ) > pt{
  39         std::forward< Fn >( fn) };
  40     future< result_t > f{ pt.get_future() };
  41     fiber{ std::move( pt), std::forward< Args >( args) ... }.detach();
  42     return f;
  43 }
  44
  45 template< typename Policy, typename Fn, typename ... Args >
  46 future<
  47         typename std::result_of<
  48                 typename std::enable_if<
  49                         detail::is_launch_policy< Policy >::value,
  50                         typename std::decay< Fn >::type
  51                 >::type( typename std::decay< Args >::type ...)
  52         >::type
  53 >
  54 async( Policy policy, Fn && fn, Args && ... args) {
  55     typedef typename std::result_of<
  56         typename std::decay< Fn >::type( typename std::decay< Args >::type ... )
  57     >::type     result_t;
  58
  59     packaged_task< result_t( typename std::decay< Args >::type ... ) > pt{
  60         std::forward< Fn >( fn) };
  61     future< result_t > f{ pt.get_future() };
  62     fiber{ policy, std::move( pt), std::forward< Args >( args) ... }.detach();
  63     return f;
  64 }
  65
  66 template< typename Policy, typename StackAllocator, typename Fn, typename ... Args >
  67 future<
  68         typename std::result_of<
  69                 typename std::enable_if<
  70                         detail::is_launch_policy< Policy >::value,
  71                         typename std::decay< Fn >::type
  72                 >::type( typename std::decay< Args >::type ... )
  73         >::type
  74 >
  75 async( Policy policy, std::allocator_arg_t, StackAllocator salloc, Fn && fn, Args && ... args) {
  76     typedef typename std::result_of<
  77         typename std::decay< Fn >::type( typename std::decay< Args >::type ... )
  78     >::type     result_t;
  79
  80     packaged_task< result_t( typename std::decay< Args >::type ... ) > pt{
  81         std::allocator_arg, salloc, std::forward< Fn >( fn) };
  82     future< result_t > f{ pt.get_future() };
  83     fiber{ policy, std::move( pt), std::forward< Args >( args) ... }.detach();
  84     return f;
  85 }
  86
  87 }}
  88
  89 #endif // BOOST_FIBERS_ASYNC_HPP