c++11 - 64 bit hash table in c++ -

i need hash table uses 64 bit hash.

to make clearer, unordered_set receives template argument hash functor takes argument of type key , return 32 bit unsigned integer.

i need similar should take template argument hash functor takes argument of type key , return 64 bit unsigned integer.

does know of such container (perferbly on header library stl)?

here popular hash function strings

size_t hash( const char * string ) {     size_t result = 0;     while( *string != 0 ) {         result = result * 31 + *string++;     }     return result; } 

making new hash functions popular past time computer people, not saying best. point result type not need bigger handle bigger strings.