[libcxx-commits] [libcxx] [libc++][chrono] Loads tzdata.zi in tzdb. (PR #74928)

[Louis Dionne via libcxx-commits]

================
@@ -0,0 +1,75 @@
+// -*- 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_TIME_ZONE_H
+#define _LIBCPP___CHRONO_TIME_ZONE_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/time_zone_types.h>
+#  include <__compare/strong_order.h>
+#  include <__config>
+#  include <string>
+#  include <string_view>
+#  include <vector>
+
+#  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 {
+
+class _LIBCPP_AVAILABILITY_TZDB time_zone {
+public:
+  explicit _LIBCPP_HIDE_FROM_ABI time_zone(string&& __name) : __name_(std::move(__name)) {}
+
+  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI string_view name() const noexcept { return __name_; }
+
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI vector<__tz::__continuation>& __continuations() { return __continuations_; }
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI const vector<__tz::__continuation>& __continuations() const {
+    return __continuations_;
+  }
+
+private:
+  string __name_;
+  // Note the first line has a name + __continuation, the other lines
+  // are just __continuations. So there is always at least one item in
+  // the vector.
+  vector<__tz::__continuation> __continuations_;
----------------
ldionne wrote:

I wonder if this is the kind of place where we'd benefit in using a pimpl idiom just to hide the implementation details from the headers. This could result in more flexibility down the line, since this is not performance sensitive AFAIU.

https://github.com/llvm/llvm-project/pull/74928