libcxx/test/std/time/time.point/time.point.arithmetic/op_-=.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 // <chrono>
  10
  11 // time_point
  12
  13 // time_point& operator-=(const duration& d);
  14 // constexpr in c++17
  15
  16 #include <chrono>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20
  21 #if TEST_STD_VER > 14
  22 constexpr bool constexpr_test()
  23 {
  24     typedef std::chrono::system_clock Clock;
  25     typedef std::chrono::milliseconds Duration;
  26     std::chrono::time_point<Clock, Duration> t(Duration(5));
  27     t -= Duration(4);
  28     return t.time_since_epoch() == Duration(1);
  29 }
  30 #endif
  31
  32 int main(int, char**)
  33 {
  34     {
  35     typedef std::chrono::system_clock Clock;
  36     typedef std::chrono::milliseconds Duration;
  37     std::chrono::time_point<Clock, Duration> t(Duration(3));
  38     t -= Duration(2);
  39     assert(t.time_since_epoch() == Duration(1));
  40     }
  41
  42 #if TEST_STD_VER > 14
  43     static_assert(constexpr_test(), "");
  44 #endif
  45
  46   return 0;
  47 }