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// Copyright 2016 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef ABSL_TIME_INTERNAL_CCTZ_TIME_ZONE_IF_H_
#define ABSL_TIME_INTERNAL_CCTZ_TIME_ZONE_IF_H_
#include <chrono>
#include <cstdint>
#include <memory>
#include <string>
#include "absl/base/config.h"
#include "absl/time/internal/cctz/include/cctz/civil_time.h"
#include "absl/time/internal/cctz/include/cctz/time_zone.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace time_internal {
namespace cctz {
// A simple interface used to hide time-zone complexities from time_zone::Impl.
// Subclasses implement the functions for civil-time conversions in the zone.
class TimeZoneIf {
public:
// Factory functions for TimeZoneIf implementations.
static std::unique_ptr<TimeZoneIf> UTC(); // never fails
static std::unique_ptr<TimeZoneIf> Make(const std::string& name);
virtual ~TimeZoneIf();
virtual time_zone::absolute_lookup BreakTime(
const time_point<seconds>& tp) const = 0;
virtual time_zone::civil_lookup MakeTime(const civil_second& cs) const = 0;
virtual bool NextTransition(const time_point<seconds>& tp,
time_zone::civil_transition* trans) const = 0;
virtual bool PrevTransition(const time_point<seconds>& tp,
time_zone::civil_transition* trans) const = 0;
virtual std::string Version() const = 0;
virtual std::string Description() const = 0;
protected:
TimeZoneIf() = default;
TimeZoneIf(const TimeZoneIf&) = delete;
TimeZoneIf& operator=(const TimeZoneIf&) = delete;
};
// Convert between time_point<seconds> and a count of seconds since the
// Unix epoch. We assume that the std::chrono::system_clock and the
// Unix clock are second aligned, and that the results are representable.
// (That is, that they share an epoch, which is required since C++20.)
inline std::int_fast64_t ToUnixSeconds(const time_point<seconds>& tp) {
return (tp - std::chrono::time_point_cast<seconds>(
std::chrono::system_clock::from_time_t(0)))
.count();
}
inline time_point<seconds> FromUnixSeconds(std::int_fast64_t t) {
return std::chrono::time_point_cast<seconds>(
std::chrono::system_clock::from_time_t(0)) +
seconds(t);
}
} // namespace cctz
} // namespace time_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_TIME_INTERNAL_CCTZ_TIME_ZONE_IF_H_