libstdc++-v3/testsuite/29_atomics/atomic/cons/value_init.cc

   1 // Copyright (C) 2020-2023 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-options "-std=gnu++2a" }
  19 // { dg-do run { target c++2a } }
  20
  21 #include <atomic>
  22
  23 #ifndef __cpp_lib_atomic_value_initialization
  24 # error "Feature test macro for atomic value-initialization is missing"
  25 #elif __cpp_lib_atomic_value_initialization < 201911L
  26 # error "Feature test macro for atomic value-initialization has wrong value"
  27 #endif
  28
  29 #include <testsuite_hooks.h>
  30
  31 struct A
  32 {
  33   constexpr A() : val(42) { }
  34   int val;
  35 };
  36
  37 constexpr std::atomic<A> a;
  38
  39 void
  40 test01()
  41 {
  42   VERIFY(a.load().val == 42);
  43   static_assert(!std::is_nothrow_default_constructible_v<std::atomic<A>>);
  44 }
  45
  46 struct B
  47 {
  48   constexpr B() noexcept : val(99) { }
  49   int val;
  50 };
  51
  52 constexpr std::atomic<B> b;
  53
  54 void
  55 test02()
  56 {
  57   VERIFY(b.load().val == 99);
  58   static_assert(std::is_nothrow_default_constructible_v<std::atomic<B>>);
  59 }
  60
  61 constexpr std::atomic<int*> c;
  62
  63 void
  64 test03()
  65 {
  66   VERIFY(c.load() == nullptr);
  67   static_assert(std::is_nothrow_default_constructible_v<std::atomic<int*>>);
  68 }
  69
  70 int
  71 main()
  72 {
  73   test01();
  74   test02();
  75   test03();
  76 }