C++ Hash function for string in unordered_map

C++ STL provides template specializations of std::hash for the various string classes. You could just specify std::string as key type for std::unordered_map:

#include <string>
#include <unordered_map>

int main()
{
    std::unordered_map<std::string, int> map;
    map["string"] = 10;
    return 0;
}