libcxx/test/std/thread/futures/futures.promise/move_assign.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 // promise& operator=(promise&& rhs);
  17
  18 #include <future>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22 #include "test_allocator.h"
  23
  24 int main(int, char**)
  25 {
  26     test_allocator_statistics alloc_stats;
  27     assert(alloc_stats.alloc_count == 0);
  28     {
  29         std::promise<int> p0(std::allocator_arg, test_allocator<int>(&alloc_stats));
  30         std::promise<int> p(std::allocator_arg, test_allocator<int>(&alloc_stats));
  31         assert(alloc_stats.alloc_count == 2);
  32         p = std::move(p0);
  33         assert(alloc_stats.alloc_count == 1);
  34         std::future<int> f = p.get_future();
  35         assert(alloc_stats.alloc_count == 1);
  36         assert(f.valid());
  37 #ifndef TEST_HAS_NO_EXCEPTIONS
  38         try
  39         {
  40             f = p0.get_future();
  41             assert(false);
  42         }
  43         catch (const std::future_error& e)
  44         {
  45             assert(e.code() == make_error_code(std::future_errc::no_state));
  46         }
  47 #endif
  48         assert(alloc_stats.alloc_count == 1);
  49     }
  50     assert(alloc_stats.alloc_count == 0);
  51     {
  52         std::promise<int&> p0(std::allocator_arg, test_allocator<int>(&alloc_stats));
  53         std::promise<int&> p(std::allocator_arg, test_allocator<int>(&alloc_stats));
  54         assert(alloc_stats.alloc_count == 2);
  55         p = std::move(p0);
  56         assert(alloc_stats.alloc_count == 1);
  57         std::future<int&> f = p.get_future();
  58         assert(alloc_stats.alloc_count == 1);
  59         assert(f.valid());
  60 #ifndef TEST_HAS_NO_EXCEPTIONS
  61         try
  62         {
  63             f = p0.get_future();
  64             assert(false);
  65         }
  66         catch (const std::future_error& e)
  67         {
  68             assert(e.code() == make_error_code(std::future_errc::no_state));
  69         }
  70 #endif
  71         assert(alloc_stats.alloc_count == 1);
  72     }
  73     assert(alloc_stats.alloc_count == 0);
  74     {
  75         std::promise<void> p0(std::allocator_arg, test_allocator<void>(&alloc_stats));
  76         std::promise<void> p(std::allocator_arg, test_allocator<void>(&alloc_stats));
  77         assert(alloc_stats.alloc_count == 2);
  78         p = std::move(p0);
  79         assert(alloc_stats.alloc_count == 1);
  80         std::future<void> f = p.get_future();
  81         assert(alloc_stats.alloc_count == 1);
  82         assert(f.valid());
  83 #ifndef TEST_HAS_NO_EXCEPTIONS
  84         try
  85         {
  86             f = p0.get_future();
  87             assert(false);
  88         }
  89         catch (const std::future_error& e)
  90         {
  91             assert(e.code() == make_error_code(std::future_errc::no_state));
  92         }
  93 #endif
  94         assert(alloc_stats.alloc_count == 1);
  95     }
  96     assert(alloc_stats.alloc_count == 0);
  97
  98   return 0;
  99 }