std::type_index::hash_code
From cppreference.com
                    
                                        
                    < cpp | types | type index
                    
                                                            
                    |   std::size_t hash_code() const;  | 
 (since C++11)  (until C++14)  | 
|
|   std::size_t hash_code() const noexcept;  | 
(since C++14) | |
Returns the hash code of the associated std::type_info object. Equivalent to calling type_info::hash_code directly.
Parameters
(none)
Return value
The hash code of the associated type_info object.
Example
| This section is incomplete Reason: no example  | 
See also
|    (C++11)  | 
   hash support for std::type_index   (class template specialization)  |