test/std/thread/thread.stoptoken/stopsource/stop_possible.pass.cpp

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: no-threads
// UNSUPPORTED: c++03, c++11, c++14, c++17
// XFAIL: availability-synchronization_library-missing

// [[nodiscard]] bool stop_possible() const noexcept;
// Returns: true if *this has ownership of a stop state; otherwise, false.

#include <cassert>
#include <stop_token>
#include <type_traits>

#include "test_macros.h"

template <class T>
concept IsStopPossibleNoexcept = requires(const T& t) {
  { t.stop_possible() } noexcept;
};

static_assert(IsStopPossibleNoexcept<std::stop_source>);

int main(int, char**) {
  // no state
  {
    const std::stop_source st{std::nostopstate};
    assert(!st.stop_possible());
  }

  // with state
  {
    const std::stop_source st;
    assert(st.stop_possible());
  }

  return 0;
}