[libcxx-commits] [libcxx] [libc++][TZDB] Adds basics of zoned_time class. (PR #94999)

[Louis Dionne via libcxx-commits]

================
@@ -0,0 +1,29 @@
+//===----------------------------------------------------------------------===//
+//
+// 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: c++03, c++11, c++14, c++17
+// UNSUPPORTED: no-filesystem, no-localization, no-tzdb
+
+// XFAIL: libcpp-has-no-experimental-tzdb
+// XFAIL: availability-tzdb-missing
+
+// <chrono>
+
+// template<class Duration, class TimeZonePtr = const time_zone*>
+//
+// If Duration is not a specialization of chrono::duration, the program is ill-formed.
+
+#include <chrono>
+
+int main(int, char**) {
+  // clang-format off
+  std::chrono::zoned_time<int> v; // expected-error@*:* {{static assertion failed due to requirement '__is_duration<int>::value': the program is ill-formed since _Duration is not a specialization of std::chrono::duration}}
----------------
ldionne wrote:

```suggestion
  std::chrono::zoned_time<int> v; // expected-error@*:* {{the program is ill-formed since _Duration is not a specialization of std::chrono::duration}}
```

I'd suggest dropping this part to avoid being too tightly coupled with Clang diagnostics. This is something we should get into the habit of doing (and also do a pass over the test suite to fix).

https://github.com/llvm/llvm-project/pull/94999