libstdc++-v3/testsuite/30_threads/packaged_task/cons/deduction.cc

   1 // // Copyright (C) 2017-2023 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-do compile { target c++17 } }
  19
  20 #include <future>
  21
  22 template<typename T, typename U> struct require_same;
  23 template<typename T> struct require_same<T, T> { using type = void; };
  24
  25 template<typename T, typename U>
  26   typename require_same<T, U>::type
  27   check_type(U&) { }
  28
  29 void f0v();
  30 void f0vn() noexcept;
  31 int f0i();
  32 int f0in() noexcept;
  33 long f1l(int&);
  34 long f1ln(double*) noexcept;
  35
  36 void
  37 test01()
  38 {
  39   std::packaged_task task1{f0v};
  40   check_type<std::packaged_task<void()>>(task1);
  41
  42   std::packaged_task task2{f0vn};
  43   check_type<std::packaged_task<void()>>(task2);
  44
  45   std::packaged_task task3{f0i};
  46   check_type<std::packaged_task<int()>>(task3);
  47
  48   std::packaged_task task4{f0in};
  49   check_type<std::packaged_task<int()>>(task4);
  50
  51   std::packaged_task task5{f1l};
  52   check_type<std::packaged_task<long(int&)>>(task5);
  53
  54   std::packaged_task task6{f1ln};
  55   check_type<std::packaged_task<long(double*)>>(task6);
  56
  57   std::packaged_task task5a{std::move(task5)};
  58   check_type<std::packaged_task<long(int&)>>(task5a);
  59
  60   std::packaged_task task6a{std::move(task6)};
  61   check_type<std::packaged_task<long(double*)>>(task6a);
  62 }
  63
  64 struct X {
  65   int operator()(const short&, void*);
  66 };
  67
  68 struct Y {
  69   void operator()(int) const & noexcept;
  70 };
  71
  72 void
  73 test02()
  74 {
  75   X x;
  76   std::packaged_task task1{x};
  77   check_type<std::packaged_task<int(const short&, void*)>>(task1);
  78
  79   Y y;
  80   std::packaged_task task2{y};
  81   check_type<std::packaged_task<void(int)>>(task2);
  82
  83   std::packaged_task task3{[&x](float) -> X& { return x; }};
  84   check_type<std::packaged_task<X&(float)>>(task3);
  85 }