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std::chrono::high_resolution_clock(3) | C++ Standard Libary | std::chrono::high_resolution_clock(3) |
NAME¶
std::chrono::high_resolution_clock - std::chrono::high_resolution_clock
Synopsis¶
Defined in header <chrono>
class high_resolution_clock; (since C++11)
Class std::chrono::high_resolution_clock represents the clock with the
smallest tick
period provided by the implementation. It may be an alias of
std::chrono::system_clock or std::chrono::steady_clock, or a third,
independent
clock.
std::chrono::high_resolution_clock meets the requirements of
TrivialClock.
Member types¶
Member type Definition
rep arithmetic type representing the number of ticks in the clock's duration
period a std::ratio type representing the tick period of the clock, in
seconds
duration std::chrono::duration<rep, period>
time_point
std::chrono::time_point<std::chrono::high_resolution_clock>
Member constants¶
true if the time between ticks is always constant, i.e.
constexpr bool is_steady calls to now() return values that increase
monotonically
[static] even in case of some external clock adjustment, otherwise
false
(public static member constant)
Member functions¶
now returns a std::chrono::time_point representing the current
value of the
[static] clock
(public static member function)
Notes¶
The high_resolution_clock is not implemented consistently across
different standard
library implementations, and its use should be avoided. It is often just an
alias
for std::chrono::steady_clock or std::chrono::system_clock, but which one it
is
depends on the library or configuration. When it is a system_clock, it is not
monotonic (e.g., the time can go backwards). For example, for gcc's libstdc++
it is
system_clock, for MSVC it is steady_clock, and for clang's libc++ it depends
on
configuration.
Generally one should just use std::chrono::steady_clock or
std::chrono::system_clock
directly instead of std::chrono::high_resolution_clock: use steady_clock for
duration measurements, and system_clock for wall-clock time.
See also¶
system_clock wall clock time from the system-wide realtime clock
(C++11) (class)
steady_clock monotonic clock that will never be adjusted
(C++11) (class)
2022.07.31 | http://cppreference.com |