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

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Defined in header `<chrono>`
template < class Rep, class Period > struct hash < std:: chrono :: duration < Rep, Period >> ;		(since C++26)

The template specialization of std::hash for std::chrono::duration allows users to obtain hashes of objects of type std:: chrono :: duration < Rep, Period > . This specialization is enabled if and only if both std:: hash < Rep > and std:: hash < Period > are enabled.

Feature-test macro	Value	Std	Feature
`__cpp_lib_chrono`	`202306L`	(C++26)	Hashing support for `std::chrono` value classes

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