test/std/utilities/time/time.duration/time.duration.arithmetic/op_--.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
//
//===----------------------------------------------------------------------===//

// <chrono>

// duration

// constexpr duration& operator--();  // constexpr in C++17

#include <chrono>
#include <cassert>

#include "test_macros.h"

#if TEST_STD_VER > 14
constexpr bool test_constexpr()
{
    std::chrono::hours h(3);
    return (--h).count() == 2;
}
#endif

int main(int, char**)
{
    {
    std::chrono::hours h(3);
    std::chrono::hours& href = --h;
    assert(&href == &h);
    assert(h.count() == 2);
    }

#if TEST_STD_VER > 14
    static_assert(test_constexpr(), "");
#endif

  return 0;
}