libcxx/test/std/thread/futures/futures.task/futures.task.members/ctor_func.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 // template <class F>
  17 //     explicit packaged_task(F&& f);
  18
  19 #include <future>
  20 #include <cassert>
  21
  22 #include "test_macros.h"
  23
  24 class A
  25 {
  26     long data_;
  27
  28 public:
  29     static int n_moves;
  30     static int n_copies;
  31
  32     explicit A(long i) : data_(i) {}
  33     A(A&& a) : data_(a.data_) {++n_moves; a.data_ = -1;}
  34     A(const A& a) : data_(a.data_) {++n_copies;}
  35
  36     long operator()(long i, long j) const {return data_ + i + j;}
  37 };
  38
  39 int A::n_moves = 0;
  40 int A::n_copies = 0;
  41
  42 int func(int i) { return i; }
  43
  44 int main(int, char**)
  45 {
  46     {
  47         std::packaged_task<double(int, char)> p(A(5));
  48         assert(p.valid());
  49         std::future<double> f = p.get_future();
  50         p(3, 97);
  51         assert(f.get() == 105.0);
  52         assert(A::n_copies == 0);
  53         assert(A::n_moves > 0);
  54     }
  55     A::n_copies = 0;
  56     A::n_copies = 0;
  57     {
  58         A a(5);
  59         std::packaged_task<double(int, char)> p(a);
  60         assert(p.valid());
  61         std::future<double> f = p.get_future();
  62         p(3, 97);
  63         assert(f.get() == 105.0);
  64         assert(A::n_copies > 0);
  65         assert(A::n_moves > 0);
  66     }
  67     {
  68         std::packaged_task<int(int)> p(&func);
  69         assert(p.valid());
  70         std::future<int> f = p.get_future();
  71         p(4);
  72         assert(f.get() == 4);
  73     }
  74     {
  75         std::packaged_task<int(int)> p(func);
  76         assert(p.valid());
  77         std::future<int> f = p.get_future();
  78         p(4);
  79         assert(f.get() == 4);
  80     }
  81
  82   return 0;
  83 }