539 lines
20 KiB
C
539 lines
20 KiB
C
|
// Copyright 2018 The Abseil Authors.
|
||
|
|
//
|
||
|
|
// 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
|
||
|
|
//
|
||
|
|
// https://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
//
|
||
|
|
// 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.
|
||
|
|
//
|
||
|
|
// -----------------------------------------------------------------------------
|
||
|
|
// File: civil_time.h
|
||
|
|
// -----------------------------------------------------------------------------
|
||
|
|
//
|
||
|
|
// This header file defines abstractions for computing with "civil time".
|
||
|
|
// The term "civil time" refers to the legally recognized human-scale time
|
||
|
|
// that is represented by the six fields `YYYY-MM-DD hh:mm:ss`. A "date"
|
||
|
|
// is perhaps the most common example of a civil time (represented here as
|
||
|
|
// an `absl::CivilDay`).
|
||
|
|
//
|
||
|
|
// Modern-day civil time follows the Gregorian Calendar and is a
|
||
|
|
// time-zone-independent concept: a civil time of "2015-06-01 12:00:00", for
|
||
|
|
// example, is not tied to a time zone. Put another way, a civil time does not
|
||
|
|
// map to a unique point in time; a civil time must be mapped to an absolute
|
||
|
|
// time *through* a time zone.
|
||
|
|
//
|
||
|
|
// Because a civil time is what most people think of as "time," it is common to
|
||
|
|
// map absolute times to civil times to present to users.
|
||
|
|
//
|
||
|
|
// Time zones define the relationship between absolute and civil times. Given an
|
||
|
|
// absolute or civil time and a time zone, you can compute the other time:
|
||
|
|
//
|
||
|
|
// Civil Time = F(Absolute Time, Time Zone)
|
||
|
|
// Absolute Time = G(Civil Time, Time Zone)
|
||
|
|
//
|
||
|
|
// The Abseil time library allows you to construct such civil times from
|
||
|
|
// absolute times; consult time.h for such functionality.
|
||
|
|
//
|
||
|
|
// This library provides six classes for constructing civil-time objects, and
|
||
|
|
// provides several helper functions for rounding, iterating, and performing
|
||
|
|
// arithmetic on civil-time objects, while avoiding complications like
|
||
|
|
// daylight-saving time (DST):
|
||
|
|
//
|
||
|
|
// * `absl::CivilSecond`
|
||
|
|
// * `absl::CivilMinute`
|
||
|
|
// * `absl::CivilHour`
|
||
|
|
// * `absl::CivilDay`
|
||
|
|
// * `absl::CivilMonth`
|
||
|
|
// * `absl::CivilYear`
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// // Construct a civil-time object for a specific day
|
||
|
|
// const absl::CivilDay cd(1969, 07, 20);
|
||
|
|
//
|
||
|
|
// // Construct a civil-time object for a specific second
|
||
|
|
// const absl::CivilSecond cd(2018, 8, 1, 12, 0, 1);
|
||
|
|
//
|
||
|
|
// Note: In C++14 and later, this library is usable in a constexpr context.
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// // Valid in C++14
|
||
|
|
// constexpr absl::CivilDay cd(1969, 07, 20);
|
||
|
|
|
||
|
|
#ifndef ABSL_TIME_CIVIL_TIME_H_
|
||
|
|
#define ABSL_TIME_CIVIL_TIME_H_
|
||
|
|
|
||
|
|
#include <string>
|
||
|
|
|
||
|
|
#include "absl/strings/string_view.h"
|
||
|
|
#include "absl/time/internal/cctz/include/cctz/civil_time.h"
|
||
|
|
|
||
|
|
namespace absl {
|
||
|
|
ABSL_NAMESPACE_BEGIN
|
||
|
|
|
||
|
|
namespace time_internal {
|
||
|
|
struct second_tag : cctz::detail::second_tag {};
|
||
|
|
struct minute_tag : second_tag, cctz::detail::minute_tag {};
|
||
|
|
struct hour_tag : minute_tag, cctz::detail::hour_tag {};
|
||
|
|
struct day_tag : hour_tag, cctz::detail::day_tag {};
|
||
|
|
struct month_tag : day_tag, cctz::detail::month_tag {};
|
||
|
|
struct year_tag : month_tag, cctz::detail::year_tag {};
|
||
|
|
} // namespace time_internal
|
||
|
|
|
||
|
|
// -----------------------------------------------------------------------------
|
||
|
|
// CivilSecond, CivilMinute, CivilHour, CivilDay, CivilMonth, CivilYear
|
||
|
|
// -----------------------------------------------------------------------------
|
||
|
|
//
|
||
|
|
// Each of these civil-time types is a simple value type with the same
|
||
|
|
// interface for construction and the same six accessors for each of the civil
|
||
|
|
// time fields (year, month, day, hour, minute, and second, aka YMDHMS). These
|
||
|
|
// classes differ only in their alignment, which is indicated by the type name
|
||
|
|
// and specifies the field on which arithmetic operates.
|
||
|
|
//
|
||
|
|
// CONSTRUCTION
|
||
|
|
//
|
||
|
|
// Each of the civil-time types can be constructed in two ways: by directly
|
||
|
|
// passing to the constructor up to six integers representing the YMDHMS fields,
|
||
|
|
// or by copying the YMDHMS fields from a differently aligned civil-time type.
|
||
|
|
// Omitted fields are assigned their minimum valid value. Hours, minutes, and
|
||
|
|
// seconds will be set to 0, month and day will be set to 1. Since there is no
|
||
|
|
// minimum year, the default is 1970.
|
||
|
|
//
|
||
|
|
// Examples:
|
||
|
|
//
|
||
|
|
// absl::CivilDay default_value; // 1970-01-01 00:00:00
|
||
|
|
//
|
||
|
|
// absl::CivilDay a(2015, 2, 3); // 2015-02-03 00:00:00
|
||
|
|
// absl::CivilDay b(2015, 2, 3, 4, 5, 6); // 2015-02-03 00:00:00
|
||
|
|
// absl::CivilDay c(2015); // 2015-01-01 00:00:00
|
||
|
|
//
|
||
|
|
// absl::CivilSecond ss(2015, 2, 3, 4, 5, 6); // 2015-02-03 04:05:06
|
||
|
|
// absl::CivilMinute mm(ss); // 2015-02-03 04:05:00
|
||
|
|
// absl::CivilHour hh(mm); // 2015-02-03 04:00:00
|
||
|
|
// absl::CivilDay d(hh); // 2015-02-03 00:00:00
|
||
|
|
// absl::CivilMonth m(d); // 2015-02-01 00:00:00
|
||
|
|
// absl::CivilYear y(m); // 2015-01-01 00:00:00
|
||
|
|
//
|
||
|
|
// m = absl::CivilMonth(y); // 2015-01-01 00:00:00
|
||
|
|
// d = absl::CivilDay(m); // 2015-01-01 00:00:00
|
||
|
|
// hh = absl::CivilHour(d); // 2015-01-01 00:00:00
|
||
|
|
// mm = absl::CivilMinute(hh); // 2015-01-01 00:00:00
|
||
|
|
// ss = absl::CivilSecond(mm); // 2015-01-01 00:00:00
|
||
|
|
//
|
||
|
|
// Each civil-time class is aligned to the civil-time field indicated in the
|
||
|
|
// class's name after normalization. Alignment is performed by setting all the
|
||
|
|
// inferior fields to their minimum valid value (as described above). The
|
||
|
|
// following are examples of how each of the six types would align the fields
|
||
|
|
// representing November 22, 2015 at 12:34:56 in the afternoon. (Note: the
|
||
|
|
// string format used here is not important; it's just a shorthand way of
|
||
|
|
// showing the six YMDHMS fields.)
|
||
|
|
//
|
||
|
|
// absl::CivilSecond : 2015-11-22 12:34:56
|
||
|
|
// absl::CivilMinute : 2015-11-22 12:34:00
|
||
|
|
// absl::CivilHour : 2015-11-22 12:00:00
|
||
|
|
// absl::CivilDay : 2015-11-22 00:00:00
|
||
|
|
// absl::CivilMonth : 2015-11-01 00:00:00
|
||
|
|
// absl::CivilYear : 2015-01-01 00:00:00
|
||
|
|
//
|
||
|
|
// Each civil-time type performs arithmetic on the field to which it is
|
||
|
|
// aligned. This means that adding 1 to an absl::CivilDay increments the day
|
||
|
|
// field (normalizing as necessary), and subtracting 7 from an absl::CivilMonth
|
||
|
|
// operates on the month field (normalizing as necessary). All arithmetic
|
||
|
|
// produces a valid civil time. Difference requires two similarly aligned
|
||
|
|
// civil-time objects and returns the scalar answer in units of the objects'
|
||
|
|
// alignment. For example, the difference between two absl::CivilHour objects
|
||
|
|
// will give an answer in units of civil hours.
|
||
|
|
//
|
||
|
|
// ALIGNMENT CONVERSION
|
||
|
|
//
|
||
|
|
// The alignment of a civil-time object cannot change, but the object may be
|
||
|
|
// used to construct a new object with a different alignment. This is referred
|
||
|
|
// to as "realigning". When realigning to a type with the same or more
|
||
|
|
// precision (e.g., absl::CivilDay -> absl::CivilSecond), the conversion may be
|
||
|
|
// performed implicitly since no information is lost. However, if information
|
||
|
|
// could be discarded (e.g., CivilSecond -> CivilDay), the conversion must
|
||
|
|
// be explicit at the call site.
|
||
|
|
//
|
||
|
|
// Examples:
|
||
|
|
//
|
||
|
|
// void UseDay(absl::CivilDay day);
|
||
|
|
//
|
||
|
|
// absl::CivilSecond cs;
|
||
|
|
// UseDay(cs); // Won't compile because data may be discarded
|
||
|
|
// UseDay(absl::CivilDay(cs)); // OK: explicit conversion
|
||
|
|
//
|
||
|
|
// absl::CivilDay cd;
|
||
|
|
// UseDay(cd); // OK: no conversion needed
|
||
|
|
//
|
||
|
|
// absl::CivilMonth cm;
|
||
|
|
// UseDay(cm); // OK: implicit conversion to absl::CivilDay
|
||
|
|
//
|
||
|
|
// NORMALIZATION
|
||
|
|
//
|
||
|
|
// Normalization takes invalid values and adjusts them to produce valid values.
|
||
|
|
// Within the civil-time library, integer arguments passed to the Civil*
|
||
|
|
// constructors may be out-of-range, in which case they are normalized by
|
||
|
|
// carrying overflow into a field of courser granularity to produce valid
|
||
|
|
// civil-time objects. This normalization enables natural arithmetic on
|
||
|
|
// constructor arguments without worrying about the field's range.
|
||
|
|
//
|
||
|
|
// Examples:
|
||
|
|
//
|
||
|
|
// // Out-of-range; normalized to 2016-11-01
|
||
|
|
// absl::CivilDay d(2016, 10, 32);
|
||
|
|
// // Out-of-range, negative: normalized to 2016-10-30T23
|
||
|
|
// absl::CivilHour h1(2016, 10, 31, -1);
|
||
|
|
// // Normalization is cumulative: normalized to 2016-10-30T23
|
||
|
|
// absl::CivilHour h2(2016, 10, 32, -25);
|
||
|
|
//
|
||
|
|
// Note: If normalization is undesired, you can signal an error by comparing
|
||
|
|
// the constructor arguments to the normalized values returned by the YMDHMS
|
||
|
|
// properties.
|
||
|
|
//
|
||
|
|
// COMPARISON
|
||
|
|
//
|
||
|
|
// Comparison between civil-time objects considers all six YMDHMS fields,
|
||
|
|
// regardless of the type's alignment. Comparison between differently aligned
|
||
|
|
// civil-time types is allowed.
|
||
|
|
//
|
||
|
|
// Examples:
|
||
|
|
//
|
||
|
|
// absl::CivilDay feb_3(2015, 2, 3); // 2015-02-03 00:00:00
|
||
|
|
// absl::CivilDay mar_4(2015, 3, 4); // 2015-03-04 00:00:00
|
||
|
|
// // feb_3 < mar_4
|
||
|
|
// // absl::CivilYear(feb_3) == absl::CivilYear(mar_4)
|
||
|
|
//
|
||
|
|
// absl::CivilSecond feb_3_noon(2015, 2, 3, 12, 0, 0); // 2015-02-03 12:00:00
|
||
|
|
// // feb_3 < feb_3_noon
|
||
|
|
// // feb_3 == absl::CivilDay(feb_3_noon)
|
||
|
|
//
|
||
|
|
// // Iterates all the days of February 2015.
|
||
|
|
// for (absl::CivilDay d(2015, 2, 1); d < absl::CivilMonth(2015, 3); ++d) {
|
||
|
|
// // ...
|
||
|
|
// }
|
||
|
|
//
|
||
|
|
// ARITHMETIC
|
||
|
|
//
|
||
|
|
// Civil-time types support natural arithmetic operators such as addition,
|
||
|
|
// subtraction, and difference. Arithmetic operates on the civil-time field
|
||
|
|
// indicated in the type's name. Difference operators require arguments with
|
||
|
|
// the same alignment and return the answer in units of the alignment.
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// absl::CivilDay a(2015, 2, 3);
|
||
|
|
// ++a; // 2015-02-04 00:00:00
|
||
|
|
// --a; // 2015-02-03 00:00:00
|
||
|
|
// absl::CivilDay b = a + 1; // 2015-02-04 00:00:00
|
||
|
|
// absl::CivilDay c = 1 + b; // 2015-02-05 00:00:00
|
||
|
|
// int n = c - a; // n = 2 (civil days)
|
||
|
|
// int m = c - absl::CivilMonth(c); // Won't compile: different types.
|
||
|
|
//
|
||
|
|
// ACCESSORS
|
||
|
|
//
|
||
|
|
// Each civil-time type has accessors for all six of the civil-time fields:
|
||
|
|
// year, month, day, hour, minute, and second.
|
||
|
|
//
|
||
|
|
// civil_year_t year()
|
||
|
|
// int month()
|
||
|
|
// int day()
|
||
|
|
// int hour()
|
||
|
|
// int minute()
|
||
|
|
// int second()
|
||
|
|
//
|
||
|
|
// Recall that fields inferior to the type's alignment will be set to their
|
||
|
|
// minimum valid value.
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// absl::CivilDay d(2015, 6, 28);
|
||
|
|
// // d.year() == 2015
|
||
|
|
// // d.month() == 6
|
||
|
|
// // d.day() == 28
|
||
|
|
// // d.hour() == 0
|
||
|
|
// // d.minute() == 0
|
||
|
|
// // d.second() == 0
|
||
|
|
//
|
||
|
|
// CASE STUDY: Adding a month to January 31.
|
||
|
|
//
|
||
|
|
// One of the classic questions that arises when considering a civil time
|
||
|
|
// library (or a date library or a date/time library) is this:
|
||
|
|
// "What is the result of adding a month to January 31?"
|
||
|
|
// This is an interesting question because it is unclear what is meant by a
|
||
|
|
// "month", and several different answers are possible, depending on context:
|
||
|
|
//
|
||
|
|
// 1. March 3 (or 2 if a leap year), if "add a month" means to add a month to
|
||
|
|
// the current month, and adjust the date to overflow the extra days into
|
||
|
|
// March. In this case the result of "February 31" would be normalized as
|
||
|
|
// within the civil-time library.
|
||
|
|
// 2. February 28 (or 29 if a leap year), if "add a month" means to add a
|
||
|
|
// month, and adjust the date while holding the resulting month constant.
|
||
|
|
// In this case, the result of "February 31" would be truncated to the last
|
||
|
|
// day in February.
|
||
|
|
// 3. An error. The caller may get some error, an exception, an invalid date
|
||
|
|
// object, or perhaps return `false`. This may make sense because there is
|
||
|
|
// no single unambiguously correct answer to the question.
|
||
|
|
//
|
||
|
|
// Practically speaking, any answer that is not what the programmer intended
|
||
|
|
// is the wrong answer.
|
||
|
|
//
|
||
|
|
// The Abseil time library avoids this problem by making it impossible to
|
||
|
|
// ask ambiguous questions. All civil-time objects are aligned to a particular
|
||
|
|
// civil-field boundary (such as aligned to a year, month, day, hour, minute,
|
||
|
|
// or second), and arithmetic operates on the field to which the object is
|
||
|
|
// aligned. This means that in order to "add a month" the object must first be
|
||
|
|
// aligned to a month boundary, which is equivalent to the first day of that
|
||
|
|
// month.
|
||
|
|
//
|
||
|
|
// Of course, there are ways to compute an answer the question at hand using
|
||
|
|
// this Abseil time library, but they require the programmer to be explicit
|
||
|
|
// about the answer they expect. To illustrate, let's see how to compute all
|
||
|
|
// three of the above possible answers to the question of "Jan 31 plus 1
|
||
|
|
// month":
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// const absl::CivilDay d(2015, 1, 31);
|
||
|
|
//
|
||
|
|
// // Answer 1:
|
||
|
|
// // Add 1 to the month field in the constructor, and rely on normalization.
|
||
|
|
// const auto normalized = absl::CivilDay(d.year(), d.month() + 1, d.day());
|
||
|
|
// // normalized == 2015-03-03 (aka Feb 31)
|
||
|
|
//
|
||
|
|
// // Answer 2:
|
||
|
|
// // Add 1 to month field, capping to the end of next month.
|
||
|
|
// const auto next_month = absl::CivilMonth(d) + 1;
|
||
|
|
// const auto last_day_of_next_month = absl::CivilDay(next_month + 1) - 1;
|
||
|
|
// const auto capped = std::min(normalized, last_day_of_next_month);
|
||
|
|
// // capped == 2015-02-28
|
||
|
|
//
|
||
|
|
// // Answer 3:
|
||
|
|
// // Signal an error if the normalized answer is not in next month.
|
||
|
|
// if (absl::CivilMonth(normalized) != next_month) {
|
||
|
|
// // error, month overflow
|
||
|
|
// }
|
||
|
|
//
|
||
|
|
using CivilSecond =
|
||
|
|
time_internal::cctz::detail::civil_time<time_internal::second_tag>;
|
||
|
|
using CivilMinute =
|
||
|
|
time_internal::cctz::detail::civil_time<time_internal::minute_tag>;
|
||
|
|
using CivilHour =
|
||
|
|
time_internal::cctz::detail::civil_time<time_internal::hour_tag>;
|
||
|
|
using CivilDay =
|
||
|
|
time_internal::cctz::detail::civil_time<time_internal::day_tag>;
|
||
|
|
using CivilMonth =
|
||
|
|
time_internal::cctz::detail::civil_time<time_internal::month_tag>;
|
||
|
|
using CivilYear =
|
||
|
|
time_internal::cctz::detail::civil_time<time_internal::year_tag>;
|
||
|
|
|
||
|
|
// civil_year_t
|
||
|
|
//
|
||
|
|
// Type alias of a civil-time year value. This type is guaranteed to (at least)
|
||
|
|
// support any year value supported by `time_t`.
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// absl::CivilSecond cs = ...;
|
||
|
|
// absl::civil_year_t y = cs.year();
|
||
|
|
// cs = absl::CivilSecond(y, 1, 1, 0, 0, 0); // CivilSecond(CivilYear(cs))
|
||
|
|
//
|
||
|
|
using civil_year_t = time_internal::cctz::year_t;
|
||
|
|
|
||
|
|
// civil_diff_t
|
||
|
|
//
|
||
|
|
// Type alias of the difference between two civil-time values.
|
||
|
|
// This type is used to indicate arguments that are not
|
||
|
|
// normalized (such as parameters to the civil-time constructors), the results
|
||
|
|
// of civil-time subtraction, or the operand to civil-time addition.
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// absl::civil_diff_t n_sec = cs1 - cs2; // cs1 == cs2 + n_sec;
|
||
|
|
//
|
||
|
|
using civil_diff_t = time_internal::cctz::diff_t;
|
||
|
|
|
||
|
|
// Weekday::monday, Weekday::tuesday, Weekday::wednesday, Weekday::thursday,
|
||
|
|
// Weekday::friday, Weekday::saturday, Weekday::sunday
|
||
|
|
//
|
||
|
|
// The Weekday enum class represents the civil-time concept of a "weekday" with
|
||
|
|
// members for all days of the week.
|
||
|
|
//
|
||
|
|
// absl::Weekday wd = absl::Weekday::thursday;
|
||
|
|
//
|
||
|
|
using Weekday = time_internal::cctz::weekday;
|
||
|
|
|
||
|
|
// GetWeekday()
|
||
|
|
//
|
||
|
|
// Returns the absl::Weekday for the given (realigned) civil-time value.
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// absl::CivilDay a(2015, 8, 13);
|
||
|
|
// absl::Weekday wd = absl::GetWeekday(a); // wd == absl::Weekday::thursday
|
||
|
|
//
|
||
|
|
inline Weekday GetWeekday(CivilSecond cs) {
|
||
|
|
return time_internal::cctz::get_weekday(cs);
|
||
|
|
}
|
||
|
|
|
||
|
|
// NextWeekday()
|
||
|
|
// PrevWeekday()
|
||
|
|
//
|
||
|
|
// Returns the absl::CivilDay that strictly follows or precedes a given
|
||
|
|
// absl::CivilDay, and that falls on the given absl::Weekday.
|
||
|
|
//
|
||
|
|
// Example, given the following month:
|
||
|
|
//
|
||
|
|
// August 2015
|
||
|
|
// Su Mo Tu We Th Fr Sa
|
||
|
|
// 1
|
||
|
|
// 2 3 4 5 6 7 8
|
||
|
|
// 9 10 11 12 13 14 15
|
||
|
|
// 16 17 18 19 20 21 22
|
||
|
|
// 23 24 25 26 27 28 29
|
||
|
|
// 30 31
|
||
|
|
//
|
||
|
|
// absl::CivilDay a(2015, 8, 13);
|
||
|
|
// // absl::GetWeekday(a) == absl::Weekday::thursday
|
||
|
|
// absl::CivilDay b = absl::NextWeekday(a, absl::Weekday::thursday);
|
||
|
|
// // b = 2015-08-20
|
||
|
|
// absl::CivilDay c = absl::PrevWeekday(a, absl::Weekday::thursday);
|
||
|
|
// // c = 2015-08-06
|
||
|
|
//
|
||
|
|
// absl::CivilDay d = ...
|
||
|
|
// // Gets the following Thursday if d is not already Thursday
|
||
|
|
// absl::CivilDay thurs1 = absl::NextWeekday(d - 1, absl::Weekday::thursday);
|
||
|
|
// // Gets the previous Thursday if d is not already Thursday
|
||
|
|
// absl::CivilDay thurs2 = absl::PrevWeekday(d + 1, absl::Weekday::thursday);
|
||
|
|
//
|
||
|
|
inline CivilDay NextWeekday(CivilDay cd, Weekday wd) {
|
||
|
|
return CivilDay(time_internal::cctz::next_weekday(cd, wd));
|
||
|
|
}
|
||
|
|
inline CivilDay PrevWeekday(CivilDay cd, Weekday wd) {
|
||
|
|
return CivilDay(time_internal::cctz::prev_weekday(cd, wd));
|
||
|
|
}
|
||
|
|
|
||
|
|
// GetYearDay()
|
||
|
|
//
|
||
|
|
// Returns the day-of-year for the given (realigned) civil-time value.
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// absl::CivilDay a(2015, 1, 1);
|
||
|
|
// int yd_jan_1 = absl::GetYearDay(a); // yd_jan_1 = 1
|
||
|
|
// absl::CivilDay b(2015, 12, 31);
|
||
|
|
// int yd_dec_31 = absl::GetYearDay(b); // yd_dec_31 = 365
|
||
|
|
//
|
||
|
|
inline int GetYearDay(CivilSecond cs) {
|
||
|
|
return time_internal::cctz::get_yearday(cs);
|
||
|
|
}
|
||
|
|
|
||
|
|
// FormatCivilTime()
|
||
|
|
//
|
||
|
|
// Formats the given civil-time value into a string value of the following
|
||
|
|
// format:
|
||
|
|
//
|
||
|
|
// Type | Format
|
||
|
|
// ---------------------------------
|
||
|
|
// CivilSecond | YYYY-MM-DDTHH:MM:SS
|
||
|
|
// CivilMinute | YYYY-MM-DDTHH:MM
|
||
|
|
// CivilHour | YYYY-MM-DDTHH
|
||
|
|
// CivilDay | YYYY-MM-DD
|
||
|
|
// CivilMonth | YYYY-MM
|
||
|
|
// CivilYear | YYYY
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// absl::CivilDay d = absl::CivilDay(1969, 7, 20);
|
||
|
|
// std::string day_string = absl::FormatCivilTime(d); // "1969-07-20"
|
||
|
|
//
|
||
|
|
std::string FormatCivilTime(CivilSecond c);
|
||
|
|
std::string FormatCivilTime(CivilMinute c);
|
||
|
|
std::string FormatCivilTime(CivilHour c);
|
||
|
|
std::string FormatCivilTime(CivilDay c);
|
||
|
|
std::string FormatCivilTime(CivilMonth c);
|
||
|
|
std::string FormatCivilTime(CivilYear c);
|
||
|
|
|
||
|
|
// absl::ParseCivilTime()
|
||
|
|
//
|
||
|
|
// Parses a civil-time value from the specified `absl::string_view` into the
|
||
|
|
// passed output parameter. Returns `true` upon successful parsing.
|
||
|
|
//
|
||
|
|
// The expected form of the input string is as follows:
|
||
|
|
//
|
||
|
|
// Type | Format
|
||
|
|
// ---------------------------------
|
||
|
|
// CivilSecond | YYYY-MM-DDTHH:MM:SS
|
||
|
|
// CivilMinute | YYYY-MM-DDTHH:MM
|
||
|
|
// CivilHour | YYYY-MM-DDTHH
|
||
|
|
// CivilDay | YYYY-MM-DD
|
||
|
|
// CivilMonth | YYYY-MM
|
||
|
|
// CivilYear | YYYY
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// absl::CivilDay d;
|
||
|
|
// bool ok = absl::ParseCivilTime("2018-01-02", &d); // OK
|
||
|
|
//
|
||
|
|
// Note that parsing will fail if the string's format does not match the
|
||
|
|
// expected type exactly. `ParseLenientCivilTime()` below is more lenient.
|
||
|
|
//
|
||
|
|
bool ParseCivilTime(absl::string_view s, CivilSecond* c);
|
||
|
|
bool ParseCivilTime(absl::string_view s, CivilMinute* c);
|
||
|
|
bool ParseCivilTime(absl::string_view s, CivilHour* c);
|
||
|
|
bool ParseCivilTime(absl::string_view s, CivilDay* c);
|
||
|
|
bool ParseCivilTime(absl::string_view s, CivilMonth* c);
|
||
|
|
bool ParseCivilTime(absl::string_view s, CivilYear* c);
|
||
|
|
|
||
|
|
// ParseLenientCivilTime()
|
||
|
|
//
|
||
|
|
// Parses any of the formats accepted by `absl::ParseCivilTime()`, but is more
|
||
|
|
// lenient if the format of the string does not exactly match the associated
|
||
|
|
// type.
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// absl::CivilDay d;
|
||
|
|
// bool ok = absl::ParseLenientCivilTime("1969-07-20", &d); // OK
|
||
|
|
// ok = absl::ParseLenientCivilTime("1969-07-20T10", &d); // OK: T10 floored
|
||
|
|
// ok = absl::ParseLenientCivilTime("1969-07", &d); // OK: day defaults to 1
|
||
|
|
//
|
||
|
|
bool ParseLenientCivilTime(absl::string_view s, CivilSecond* c);
|
||
|
|
bool ParseLenientCivilTime(absl::string_view s, CivilMinute* c);
|
||
|
|
bool ParseLenientCivilTime(absl::string_view s, CivilHour* c);
|
||
|
|
bool ParseLenientCivilTime(absl::string_view s, CivilDay* c);
|
||
|
|
bool ParseLenientCivilTime(absl::string_view s, CivilMonth* c);
|
||
|
|
bool ParseLenientCivilTime(absl::string_view s, CivilYear* c);
|
||
|
|
|
||
|
|
namespace time_internal { // For functions found via ADL on civil-time tags.
|
||
|
|
|
||
|
|
// Streaming Operators
|
||
|
|
//
|
||
|
|
// Each civil-time type may be sent to an output stream using operator<<().
|
||
|
|
// The result matches the string produced by `FormatCivilTime()`.
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// absl::CivilDay d = absl::CivilDay(1969, 7, 20);
|
||
|
|
// std::cout << "Date is: " << d << "\n";
|
||
|
|
//
|
||
|
|
std::ostream& operator<<(std::ostream& os, CivilYear y);
|
||
|
|
std::ostream& operator<<(std::ostream& os, CivilMonth m);
|
||
|
|
std::ostream& operator<<(std::ostream& os, CivilDay d);
|
||
|
|
std::ostream& operator<<(std::ostream& os, CivilHour h);
|
||
|
|
std::ostream& operator<<(std::ostream& os, CivilMinute m);
|
||
|
|
std::ostream& operator<<(std::ostream& os, CivilSecond s);
|
||
|
|
|
||
|
|
} // namespace time_internal
|
||
|
|
|
||
|
|
ABSL_NAMESPACE_END
|
||
|
|
} // namespace absl
|
||
|
|
|
||
|
|
#endif // ABSL_TIME_CIVIL_TIME_H_
|