std::hash<std::type_index> (3) - Linux Manuals

std::hash<std::type_index>: std::hash<std::type_index>

NAME

std::hash<std::type_index> - std::hash<std::type_index>

Synopsis

Defined in header <typeindex>
template<> struct hash<type_index>; (since C++11)

The template specialization of std::hash for std::type_index allows users to obtain hashes of objects of type std::type_index.
The member operator() effectively returns the same value as hash_code().