[libcxx-commits] [libcxx] [libc++][chrono] Loads leap-seconds.list in tzdb. (PR #82113)

[Mark de Wever via libcxx-commits]

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@@ -0,0 +1,126 @@
+// -*- 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_LEAP_SECOND_H
+#define _LIBCPP___CHRONO_LEAP_SECOND_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 <__compare/ordering.h>
+#  include <__compare/three_way_comparable.h>
+#  include <__config>
+
+#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#    pragma GCC system_header
+#  endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#  if _LIBCPP_STD_VER >= 20
+
+namespace chrono {
+
+class leap_second {
+public:
+  struct __constructor_tag;
+  [[nodiscard]]
+  _LIBCPP_HIDE_FROM_ABI explicit constexpr leap_second(__constructor_tag&&, sys_seconds __date, seconds __value)
+      : __date_(__date), __value_(__value) {}
+
+  _LIBCPP_HIDE_FROM_ABI leap_second(const leap_second&)            = default;
+  _LIBCPP_HIDE_FROM_ABI leap_second& operator=(const leap_second&) = default;
+
+  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr sys_seconds date() const noexcept { return __date_; }
+
+  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr seconds value() const noexcept { return __value_; }
+
+private:
+  sys_seconds __date_;
+  seconds __value_;
+};
+
+_LIBCPP_HIDE_FROM_ABI inline constexpr bool operator==(const leap_second& __x, const leap_second& __y) {
+  return __x.date() == __y.date();
+}
+
+_LIBCPP_HIDE_FROM_ABI inline constexpr strong_ordering operator<=>(const leap_second& __x, const leap_second& __y) {
+  return __x.date() <=> __y.date();
+}
+
+template <class _Duration>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator==(const leap_second& __x, const sys_time<_Duration>& __y) {
+  return __x.date() == __y;
+}
+
+template <class _Duration>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator<(const leap_second& __x, const sys_time<_Duration>& __y) {
+  return __x.date() < __y;
+}
+
+template <class _Duration>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator<(const sys_time<_Duration>& __x, const leap_second& __y) {
+  return __x < __y.date();
+}
+
+template <class _Duration>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator>(const leap_second& __x, const sys_time<_Duration>& __y) {
+  return __y < __x;
+}
+
+template <class _Duration>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator>(const sys_time<_Duration>& __x, const leap_second& __y) {
+  return __y < __x;
+}
+
+template <class _Duration>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator<=(const leap_second& __x, const sys_time<_Duration>& __y) {
+  return !(__y < __x);
+}
+
+template <class _Duration>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator<=(const sys_time<_Duration>& __x, const leap_second& __y) {
+  return !(__y < __x);
+}
+
+template <class _Duration>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator>=(const leap_second& __x, const sys_time<_Duration>& __y) {
+  return !(__x < __y);
+}
+
+template <class _Duration>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator>=(const sys_time<_Duration>& __x, const leap_second& __y) {
+  return !(__x < __y);
+}
+
+#    ifndef _LIBCPP_COMPILER_GCC
+// This requirement cause a compilation loop in GCC-13 and running out of memory.
+// TODO TZDB Test whether GCC-14 fixes this.
+template <class _Duration>
+  requires three_way_comparable_with<sys_seconds, sys_time<_Duration>>
+_LIBCPP_HIDE_FROM_ABI constexpr auto operator<=>(const leap_second& __x, const sys_time<_Duration>& __y) {
+  return __x.date() <=> __y;
+}
+#    endif
----------------
mordante wrote:

@cor3ntin Thanks for filing the LWG-issue! 
@zyn0217 @cor3ntin I've filed https://github.com/llvm/llvm-project/issues/104700, lets continue the discussion there. I'll try to look at this issue soon.

https://github.com/llvm/llvm-project/pull/82113