[libcxx-commits] [libcxx] [libc++] Add missing C++20 [time.point.arithmetic] (PR #143165)

[Hristo Hristov via libcxx-commits]

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@@ -0,0 +1,35 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+// REQUIRES: std-at-least-c++20
+
+// <chrono>
+
+// time_point
+
+// constexpr time_point operator--(int);
+
+#include <cassert>
+#include <chrono>
+
+#include "test_macros.h"
+
+constexpr bool test() {
+  using Clock    = std::chrono::system_clock;
+  using Duration = std::chrono::milliseconds;
+  std::chrono::time_point<Clock, Duration> t1{Duration{3}};
+  std::chrono::time_point<Clock, Duration> t2{t1--};
+  assert(t1.time_since_epoch() == Duration{2});
+  assert(t2.time_since_epoch() == Duration{3});
+  return true;
+}
+
+int main(int, char**) {
+  assert(test());
----------------
Zingam wrote:

```suggestion
  test();
```

https://github.com/llvm/llvm-project/pull/143165