ceph/src/boost/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_type;
  37
  38     packaged_task< result_type( typename std::decay< Args >::type ... ) > pt{
  39         std::forward< Fn >( fn) };
  40     future< result_type > 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_type;
  58
  59     packaged_task< result_type( typename std::decay< Args >::type ... ) > pt{
  60         std::forward< Fn >( fn) };
  61     future< result_type > 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_type;
  79
  80     packaged_task< result_type( typename std::decay< Args >::type ... ) > pt{
  81         std::forward< Fn >( fn) };
  82     future< result_type > f{ pt.get_future() };
  83     fiber{ policy, std::allocator_arg, salloc,
  84         std::move( pt), std::forward< Args >( args) ... }.detach();
  85     return f;
  86 }
  87
  88 template< typename Policy, typename StackAllocator, typename Allocator, typename Fn, typename ... Args >
  89 future<
  90     typename std::result_of<
  91         typename std::enable_if<
  92             detail::is_launch_policy< Policy >::value,
  93             typename std::decay< Fn >::type
  94         >::type( typename std::decay< Args >::type ... )
  95     >::type
  96 >
  97 async( Policy policy, std::allocator_arg_t, StackAllocator salloc, Allocator alloc, Fn && fn, Args ... args) {
  98     typedef typename std::result_of<
  99         typename std::decay< Fn >::type( typename std::decay< Args >::type ... )
 100     >::type     result_type;
 101
 102     packaged_task< result_type( typename std::decay< Args >::type ... ) > pt{
 103         std::allocator_arg, alloc, std::forward< Fn >( fn) };
 104     future< result_type > f{ pt.get_future() };
 105     fiber{ policy, std::allocator_arg, salloc,
 106         std::move( pt), std::forward< Args >( args) ... }.detach();
 107     return f;
 108 }
 109
 110 }}
 111
 112 #endif // BOOST_FIBERS_ASYNC_HPP