23 Strings library [strings]

23.3 String view classes [string.view]

23.3.6 Hash support [string.view.hash]

template<> struct hash<string_view>;
template<> struct hash<u8string_view>;
template<> struct hash<u16string_view>;
template<> struct hash<u32string_view>;
template<> struct hash<wstring_view>;

The specialization is enabled ([unord.hash]).

[Note 1:

The hash value of a string view object is equal to the hash value of the corresponding string object ([basic.string.hash]).

— end note]