std::hash

1	`template<size_t` `N>` `struct` `hash<bitset<N>>;`

(since C++11)

The template specialization of std::hash for std::bitset<N> allows users to obtain hashes of objects of type std::bitset<N>.

Example

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

#include <iostream>
#include <bitset>
#include <functional>
  
int main()
{
    std::bitset<4> b1(1);
    std::bitset<4> b2(2);
    std::bitset<4> b3(b2);
  
    std::hash<std::bitset<4>> hash_fn;
  
    size_t h1 = hash_fn(b1);
    size_t h2 = hash_fn(b2);
    size_t h3 = hash_fn(b3);
  
    std::cout << h1 << '\n';
    std::cout << h2 << '\n';
    std::cout << h3 << '\n';
}

Output:

67918732
118251589
118251589

std::hash

Example

See also