libcxx/test/std/thread/thread.stoptoken/stoptoken/equals.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: libcpp-has-no-experimental-stop_token
  11 // UNSUPPORTED: c++03, c++11, c++14, c++17
  12 // XFAIL: availability-synchronization_library-missing
  13
  14 // [[nodiscard]] bool operator==(const stop_token& lhs, const stop_token& rhs) noexcept;
  15 // Returns: true if lhs and rhs have ownership of the same stop state or if both lhs and rhs do not have ownership of a stop state; otherwise false.
  16
  17 // synthesized operator != also tested.
  18
  19 #include <cassert>
  20 #include <concepts>
  21 #include <stop_token>
  22 #include <type_traits>
  23
  24 #include "test_macros.h"
  25
  26 // LWG 3254 is related.
  27 template <class T>
  28 concept IsNoThrowEqualityComparable = requires(const T& t1, const T& t2) {
  29   { t1 == t2 } noexcept;
  30 };
  31
  32 template <class T>
  33 concept IsNoThrowInequalityComparable = requires(const T& t1, const T& t2) {
  34   { t1 != t2 } noexcept;
  35 };
  36
  37 static_assert(IsNoThrowEqualityComparable<std::stop_token>);
  38 static_assert(IsNoThrowInequalityComparable<std::stop_token>);
  39
  40 int main(int, char**) {
  41   // both no state
  42   {
  43     const std::stop_token st1;
  44     const std::stop_token st2;
  45     assert(st1 == st2);
  46     assert(!(st1 != st2));
  47   }
  48
  49   // only one has no state
  50   {
  51     std::stop_source ss;
  52     const std::stop_token st1;
  53     const auto st2 = ss.get_token();
  54     assert(!(st1 == st2));
  55     assert(st1 != st2);
  56   }
  57
  58   // both has states. same source
  59   {
  60     std::stop_source ss;
  61     const auto st1 = ss.get_token();
  62     const auto st2 = ss.get_token();
  63     assert(st1 == st2);
  64     assert(!(st1 != st2));
  65   }
  66
  67   // both has states. different sources with same states
  68   {
  69     std::stop_source ss1;
  70     auto ss2 = ss1;
  71     const auto st1 = ss1.get_token();
  72     const auto st2 = ss2.get_token();
  73     assert(st1 == st2);
  74     assert(!(st1 != st2));
  75   }
  76
  77   // both has states. different sources with different states
  78   {
  79     std::stop_source ss1;
  80     std::stop_source ss2;
  81     const auto st1 = ss1.get_token();
  82     const auto st2 = ss2.get_token();
  83     assert(!(st1 == st2));
  84     assert(st1 != st2);
  85   }
  86
  87   return 0;
  88 }