std::hash<std::chrono::duration>

 

C++

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自立实现与有宿主实现

语言

标准库

标准库标头

具名要求

功能特性测试宏 (C++20)

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元编程库 (C++11)

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工具库

语言支持 类型支持（基本类型、 RTTI） 库功能特性测试宏 (C++20) 动态内存管理 程序工具 协程支持 (C++20) 变参数函数 is_constant_evaluated (C++20) is_within_lifetime (C++26) initializer_list (C++11) source_location (C++20) 三路比较 (C++20) three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20) is_eqis_neqis_ltis_lteqis_gtis_gteq (C++20)(C++20)(C++20)(C++20)(C++20)(C++20)

通用工具 日期和时间 函数对象 格式化库 (C++20) bitset hash (C++11) 关系运算符 (C++20 中弃用) rel_ops::operator!=rel_ops::operator> rel_ops::operator<=rel_ops::operator>= 整数比较函数 cmp_equalcmp_lesscmp_less_than (C++20)(C++20)(C++20) cmp_not_equalcmp_greatercmp_greater_than (C++20)(C++20)(C++20) in_range (C++20) swap 与类型运算 swap ranges::swap (C++20) exchange (C++14) declval (C++11) to_underlying (C++23) forward (C++11) forward_like (C++23) move (C++11) move_if_noexcept (C++11) as_const (C++17) 常用词汇类型 pair tuple (C++11) optional (C++17) any (C++17) variant (C++17) tuple_size (C++11) tuple_element (C++11) apply (C++17) make_from_tuple (C++17) expected (C++23) 初等字符串转换 to_chars (C++17) from_chars (C++17) chars_format (C++17) to_chars_result (C++17) from_chars_result (C++17)

 

日期和时间工具

时间点
time_point (C++11)	clock_time_conversion (C++20)	clock_cast (C++20)
时长
duration (C++11)
时钟
system_clock (C++11) steady_clock (C++11) high_resolution_clock (C++11)	is_clock (C++20) utc_clock (C++20) tai_clock (C++20)	gps_clock (C++20) file_clock (C++20) local_t (C++20)
当天时刻
is_amis_pm (C++20)(C++20)	make12make24 (C++20)(C++20)	hh_mm_ss (C++20)
日历
day (C++20) month (C++20) year (C++20) weekday (C++20) operator/ (C++20) year_month_day (C++20)	year_month_day_last (C++20) year_month_weekday (C++20) year_month_weekday_last (C++20)       weekday_indexed (C++20) weekday_last (C++20) month_day (C++20)	month_day_last (C++20) month_weekday (C++20) month_weekday_last (C++20) year_month (C++20) last_speclast (C++20)(C++20)
时区
tzdb (C++20) tzdb_list (C++20) get_tzdbget_tzdb_listreload_tzdbremote_version (C++20)(C++20)(C++20)(C++20) sys_info (C++20)	local_info (C++20) nonexistent_local_time (C++20) ambiguous_local_time (C++20) locate_zone (C++20) current_zone (C++20) time_zone (C++20) choose (C++20)	zoned_traits (C++20) zoned_time (C++20) time_zone_link (C++20) leap_second (C++20) leap_second_info (C++20) get_leap_second_info (C++20)
chrono I/O
parse (C++20)
C 风格日期和时间

 

std::chrono::duration

成员函数
duration::duration duration::operator= duration::count duration::zero duration::min duration::max duration::operator+duration::operator-	duration::operator++duration::operator-- duration::operator+=duration::operator-=duration::operator*=duration::operator/=duration::operator%=
非成员函数
operator+operator-operator*operator/operator% operator==operator!=operator<operator<=operator>operator>=operator<=> (C++20 前)(C++20) operator<< (C++20)	duration_cast floor (C++17) ceil (C++17) round (C++17) abs (C++17) operator""h (C++14) operator""min (C++14) operator""s (C++14) operator""ms (C++14) operator""us (C++14) operator""ns (C++14) from_stream (C++20)
辅助类
common_type treat_as_floating_point      duration_values	formatter<std::chrono::duration> (C++20) hash<std::chrono::duration> (C++26)

 

在标头 <chrono> 定义
template< class Rep, class Period > struct hash<std::chrono::duration<Rep, Period>>;		(C++26 起)

std::hash 对 std::chrono::duration 的模板特化允许用户获得 std::chrono::duration<Rep, Period> 对象的散列值。此特化只有在 std::hash<Rep> 和 std::hash<Period> 都启用时才会启用。

注解

功能特性测试宏	值	标准	注释
__cpp_lib_chrono	202306L	(C++26)	std::chrono 值类的散列支持

参阅

hash (C++11)

散列函数对象 (类模板)