class template specialization
<bitset>

std::hash<bitset>

template <class T> struct hash;              // unspecialized
template <size_t N> struct hash<bitset<N>>;  // bitset specialization
Hash for bitset
Unary function object class that defines the hash specialization for bitset.

The functional call returns a hash value based on the bitset passed as argument: A hash value is a value that depends solely on its argument, returning always the same value for the same argument. The value returned shall have a small likelihood of being the same as the one returned for a different argument (with chances of collision approaching 1/numeric_limits<size_t>::max).

This allows the use of bitset objects as keys for unordered containers (such as unordered_set or unordered_map).

See hash for additional information.

Member functions

operator()
Returns a hash value for its argument, as a value of type size_t.
size_t is an unsigned integral type.