hash Class
Computes hash code for a value.
template<class Ty>
struct hash
: public unary_function<Ty, size_t> {
size_t operator()(Ty _Val) const;
};
Remarks
The member function defines a hash function, suitable for mapping values of type Ty to a distribution of index values. The member operator returns a hash code for _Val, suitable for use with template classes unordered_map, unordered_multimap, unordered_set, and unordered_multiset. Ty may be any scalar type, string, wstring, error_code, error_condition, u16string, or u32string.
Example
// std_tr1__functional__hash.cpp
// compile with: /EHsc
#include <functional>
#include <iostream>
#include <unordered_set>
int main()
{
std::unordered_set<int, std::hash<int> > c0;
c0.insert(3);
std::cout << *c0.find(3) << std::endl;
return (0);
}
3
Requirements
Header: <functional>
Namespace: std