#ifndef HASHER_H_INCLUDED
#define HASHER_H_INCLUDED

#include <string>

// Some sample hash functions
//
// They should return unsigned values, as equally-distributed as
// possible over the range of unsigned values.

class Hasher {
  public:
    unsigned operator()(int n) const {
	return n;			// That was easy!
    }

    // The FNV-1a hashing algorithm.
    // https://wikipedia.org/wiki/Fowler–Noll–Vo_hash_function#FNV-1a_hash
    unsigned operator()(const std::string &s) const {
	unsigned sum = 0x811c9dc5;
	for (char c : s) {
	    sum ^= static_cast<unsigned char>(c);
	    sum *= 16777619;
	}
	return sum;
    }
};

#endif /* HASHER_H_INCLUDED */