How do I implement a hash function in C++11?

How do I implement a hash function in C++11?

To implement a hash function in C++11, you can use the std::hash template. Here's a simple example:

Can you show me a complete example?

Sure! Here's a complete example of a hash function for a custom struct:

#include <iostream>
#include <functional>

struct MyStruct {
    int x;
    int y;
};

namespace std {
    template <>
    struct hash<MyStruct> {
        size_t operator()(const MyStruct& s) const {
            return hash<int>()(s.x) ^ hash<int>()(s.y);
        }
    };
}

int main() {
    MyStruct s1 = {1, 2};
    std::cout << "Hash: " << std::hash<MyStruct>()(s1) << std::endl;
    return 0;
}

What does the ^ operator do in the hash function?

The ^ operator is the bitwise XOR operator. It combines the hash values of x and y to produce a single hash value, helping to reduce collisions.