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

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // UNSUPPORTED: no-threads
  10 // UNSUPPORTED: c++03
  11
  12 // <future>
  13
  14 // class promise<R>
  15
  16 // future<R> get_future();
  17
  18 #include <future>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22
  23 int main(int, char**)
  24 {
  25     {
  26         std::promise<double> p;
  27         std::future<double> f = p.get_future();
  28         p.set_value(105.5);
  29         assert(f.get() == 105.5);
  30     }
  31 #ifndef TEST_HAS_NO_EXCEPTIONS
  32     {
  33         std::promise<double> p;
  34         std::future<double> f = p.get_future();
  35         try
  36         {
  37             f = p.get_future();
  38             assert(false);
  39         }
  40         catch (const std::future_error& e)
  41         {
  42             assert(e.code() ==  make_error_code(std::future_errc::future_already_retrieved));
  43         }
  44     }
  45     {
  46         std::promise<double> p;
  47         std::promise<double> p0 = std::move(p);
  48         try
  49         {
  50             std::future<double> f = p.get_future();
  51             assert(false);
  52         }
  53         catch (const std::future_error& e)
  54         {
  55             assert(e.code() ==  make_error_code(std::future_errc::no_state));
  56         }
  57     }
  58 #endif
  59
  60   return 0;
  61 }