hash Structure (C++ Standard Library)
Defines a member function that returns a value that's uniquely determined by Val. The member function defines a hash function that's suitable for mapping values of type thread::id to a distribution of index values.
Syntax
template <>
struct hash<thread::id> :
public unary_function<thread::id, size_t>
{
size_t operator()(thread::id Val) const;
};
Requirements
Header: <thread>
Namespace: std