std::chrono::clock_cast
Defined in header <chrono> | ||
---|---|---|
template <class Dest, class Source, class Duration> auto clock_cast(const std::chrono::time_point<Source, Duration>& t); | (since C++20) |
Converts the time point t
of a clock Source
to an equivalent time point of the clock Dest
, using std::chrono::system_clock
and/or std::chrono::utc_clock
as intermediaries if necessary.
- If the expression
std::chrono::clock_time_conversion<Dest, Source>{}(t)
is well-formed, returns the result of that expression. - Otherwise, if at least one of the following two expressions are well-formed, then
- If both expression are well-formed, the conversion is ambiguous, and the program is ill-formed.
- Otherwise, exactly one of the two expressions is well-formed; the result of that expression is returned.
1)
std::chrono::clock_time_conversion<Dest, std::chrono::system_clock>{}(
std::chrono::clock_time_conversion<std::chrono::system_clock, Source>{}(t))
2)
std::chrono::clock_time_conversion<Dest, std::chrono::utc_clock>{}(
std::chrono::clock_time_conversion<std::chrono::utc_clock, Source>{}(t))
- Otherwise, if at least one of the following two expressions are well-formed, then
- If both expression are well-formed, the conversion is ambiguous, and the program is ill-formed.
- Otherwise, exactly one of the two expressions is well-formed; the result of that expression is returned.
1)
std::chrono::clock_time_conversion<Dest, std::chrono::utc_clock>{}(
std::chrono::clock_time_conversion<std::chrono::utc_clock, std::chrono::system_clock>{}(
std::chrono::clock_time_conversion.
<std::chrono::system_clock, Source>{}(t)))
2)
std::chrono::clock_time_conversion<Dest, std::chrono::system_clock>{}(
std::chrono::clock_time_conversion<std::chrono::system_clock, std::chrono::utc_clock>{}(
std::chrono::clock_time_conversion.
<std::chrono::utc_clock, Source>{}(t)))
- Otherwise, this function does not participate in overload resolution.
Return value
The result of the conversion, determined as described above.
Example
See also
(C++20) | traits class defining how to convert time points of one clock to another (class template) |
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