std::hash <std::experimental::optional>

From cppreference.com
Defined in header <experimental/optional>
template<class T>
struct hash<std::experimental::optional<T>>;
(library fundamentals TS)

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

[edit] 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.

[edit] Example

[edit] See also

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