std::hash

Defined in header <string>

template<> struct hash<std::string>;
template<> struct hash<std::wstring>;
template<> struct hash<std::u16string>;
template<> struct hash<std::u32string>;

(since C++11)

The template specializations of std::hash for the various string classes allow users to obtain hashes of strings.

Example

The following code shows one possible output of a hash function used on a string:

#include <iostream>
#include <string>
#include <functional>
  
int main()
{
    std::string s = "Stand back! I've got jimmies!";
    std::hash<std::string> hash_fn;
  
    size_t hash = hash_fn(s);
  
    std::cout << hash << '\n';
}

Output:

1	`325378910`

std::hash

Example

See also