libcxx/test/std/thread/futures/futures.task/futures.task.members/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 packaged_task<R(ArgTypes...)>
  15
  16 // future<R> get_future();
  17
  18 #include <future>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22
  23 class A
  24 {
  25     long data_;
  26
  27 public:
  28     explicit A(long i) : data_(i) {}
  29
  30     long operator()(long i, long j) const {return data_ + i + j;}
  31 };
  32
  33 int main(int, char**)
  34 {
  35     {
  36         std::packaged_task<double(int, char)> p(A(5));
  37         std::future<double> f = p.get_future();
  38         p(3, 97);
  39         assert(f.get() == 105.0);
  40     }
  41 #ifndef TEST_HAS_NO_EXCEPTIONS
  42     {
  43         std::packaged_task<double(int, char)> p(A(5));
  44         std::future<double> f = p.get_future();
  45         try
  46         {
  47             f = p.get_future();
  48             assert(false);
  49         }
  50         catch (const std::future_error& e)
  51         {
  52             assert(e.code() ==  make_error_code(std::future_errc::future_already_retrieved));
  53         }
  54     }
  55     {
  56         std::packaged_task<double(int, char)> p;
  57         try
  58         {
  59             std::future<double> f = p.get_future();
  60             assert(false);
  61         }
  62         catch (const std::future_error& e)
  63         {
  64             assert(e.code() ==  make_error_code(std::future_errc::no_state));
  65         }
  66     }
  67 #endif
  68
  69   return 0;
  70 }