test/std/thread/futures/futures.promise/get_future.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is dual licensed under the MIT and the University of Illinois Open
   6 // Source Licenses. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // UNSUPPORTED: libcpp-has-no-threads
  11 // UNSUPPORTED: c++98, c++03
  12
  13 // <future>
  14
  15 // class promise<R>
  16
  17 // future<R> get_future();
  18
  19 #include <future>
  20 #include <cassert>
  21
  22 #include "test_macros.h"
  23
  24 int main()
  25 {
  26     {
  27         std::promise<double> p;
  28         std::future<double> f = p.get_future();
  29         p.set_value(105.5);
  30         assert(f.get() == 105.5);
  31     }
  32 #ifndef TEST_HAS_NO_EXCEPTIONS
  33     {
  34         std::promise<double> p;
  35         std::future<double> f = p.get_future();
  36         try
  37         {
  38             f = p.get_future();
  39             assert(false);
  40         }
  41         catch (const std::future_error& e)
  42         {
  43             assert(e.code() ==  make_error_code(std::future_errc::future_already_retrieved));
  44         }
  45     }
  46     {
  47         std::promise<double> p;
  48         std::promise<double> p0 = std::move(p);
  49         try
  50         {
  51             std::future<double> f = p.get_future();
  52             assert(false);
  53         }
  54         catch (const std::future_error& e)
  55         {
  56             assert(e.code() ==  make_error_code(std::future_errc::no_state));
  57         }
  58     }
  59 #endif
  60 }