system_clock度量 Unix 时间(即从协调世界时 (UTC) 1970 年 1 月 1 日星期四 00:00:00 开始的时间,不计闰秒)。 (C++20 起) 时间点族 定义于命名空间std::chrono template<classDuration> usingsys_time=std::chrono::time_point<std::chrono::system_clock, Duration>; ...
static std::chrono::system_clock::time_point from_time_t( std::time_t t ) noexcept; (C++11 起) 用两个类型间的较低精度,转换 t 为时间点类型。 若time_point 拥有较低精度,则舍入还是截断值是实现定义的。 参数t - 要转换的 std::time_t 值...
Example Run this code #include <chrono>#include <iostream>intmain(){constautonow=std::chrono::system_clock::now();conststd::time_tt_c=std::chrono::system_clock::to_time_t(now);std::cout<<"The system clock is currently at "<<std::ctime(&t_c);} ...
4.12.2.1 The clock function See also ctimectime_s (deprecated in C23)(C11) converts atime_tobject to a textual representation (function) time returns the current calendar time of the system as time since epoch (function) C++ documentationforclock...
Clock Selection Time Support GUID Support Sequence Number Support Exception Codes Return Codes Status Kinds QoS Policies ASYNCHRONOUS_PUBLISHER AVAILABILITY BATCH DATABASE DATA_READER_PROTOCOL DATA_READER_RESOURCE_LIMITS DATA_WRITER_PROTOCOL DATA_WRITER_RESOURCE_LIMITS DEADLINE DESTINATION_ORDER DISCOVERY DISCOV...
{ // 老办法 std::time_t oldt = std::time({}); std::this_thread::sleep_for(2700ms); // 新办法 auto const now = std::chrono::system_clock::now(); std::time_t newt = std::chrono::system_clock::to_time_t(now); std::cout << "newt - oldt == " << newt - oldt <...
通常它只是 std::chrono::steady_clock 或std::chrono::system_clock 的别名,但具体是哪个取决于库或配置。它是 system_clock 时不是单调的(即时间能后退)。例如:如 2023 年所知,libstdc++ 中它是 system_clock 的别名“直到高于纳秒的定义变得可行”[1],MSVC 中它是 steady_clock 的别名[2],而 libc++ ...
C++ Date and time library std::chrono::system_clock template< class CharT, class Traits, class Duration, class Alloc = std::allocator<CharT> > std::basic_istream<CharT, Traits>& from_stream( std::basic_istream<CharT, Traits>& is, const CharT* fmt, std::chrono::sys_time<Duration>&...
() << "s\n"; // Before C++20std::cout<<elapsed_seconds<<'\n';// C++20's chrono::duration operator<<// Prints UTC and local time.constautotp_utc{std::chrono::system_clock::now()};std::cout<<"Current time 'UTC' is: "<<tp_utc<<"\n""Current time 'Local' is: "<<std:...
(24); auto epoch_time = std::chrono::system_clock::to_time_t(p0); std::cout << "epoch: " << std::ctime(&epoch_time); auto today_time = std::chrono::system_clock::to_time_t(p1); std::cout << "today: " << std::ctime(&today_time); std::cout << "hours since epoch...