[libcxx-commits] [libcxx] [libc++][chrono] Adds the sys_info class. (PR #85619)

[via libcxx-commits]

================
@@ -0,0 +1,53 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// For information see https://libcxx.llvm.org/DesignDocs/TimeZone.html
+
+#ifndef _LIBCPP___CHRONO_SYS_INFO_H
+#define _LIBCPP___CHRONO_SYS_INFO_H
+
+#include <version>
+// Enable the contents of the header only when libc++ was built with experimental features enabled.
+#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_TZDB)
+
+#  include <__chrono/duration.h>
+#  include <__chrono/system_clock.h>
+#  include <__chrono/time_point.h>
+#  include <__config>
+#  include <string>
+
+#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#    pragma GCC system_header
+#  endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#  if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_TIME_ZONE_DATABASE) && !defined(_LIBCPP_HAS_NO_FILESYSTEM) &&   \
+      !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+
+namespace chrono {
+
+struct sys_info {
----------------
EricWF wrote:

Please add the tests @ldionne requested. 

It actually tests that we have the correct declaration order of objects in the struct.

Also compile time tests are worse than tests that both compile and run. We can't catch compiler bugs as easily when we exercise less of the compiler.

https://github.com/llvm/llvm-project/pull/85619