std::hash <std::optional>

 

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Helper classes

hash

 

Defined in header <optional>
template<class T> struct hash<std::optional<T>>;		(since C++14)

The template specialization of std::hash for the std::optional class allows users to obtain hashes of the values contained in optional objects.

Template parameters

T

-

the type of the value contained in optional object. The specialization std::hash<T> must meet the requirements of class template hash.

See also

hash (C++11)	hash function object (class template)