What are some examples of hash functions in C++?

Can you give me some examples of hash functions in C++?

Sure! Some common hash functions in C++ include std::hash, MurmurHash, and SHA-256.

How does std::hash work?

std::hash is a template class in C++ that provides a default hash function for various types, allowing you to use it in hash tables.

What about MurmurHash? Is it better than std::hash?

MurmurHash is known for its speed and good distribution, making it suitable for non-cryptographic purposes, often outperforming std::hash.

Can you show me a code example of using SHA-256 in C++?

Certainly! You can use libraries like OpenSSL to implement SHA-256. Here's a simple example:

#include <openssl/sha.h>
#include <iostream>
#include <iomanip>

void sha256(const std::string& str, unsigned char outputBuffer[SHA256_DIGEST_LENGTH]) {
    SHA256_CTX ctx;
    SHA256_Init(&ctx);
    SHA256_Update(&ctx, str.c_str(), str.size());
    SHA256_Final(outputBuffer, &ctx);
}

int main() {
    std::string data = "Hello, World!";
    unsigned char hash[SHA256_DIGEST_LENGTH];
    sha256(data, hash);
    std::cout << "SHA-256: ";
    for(int i = 0; i < SHA256_DIGEST_LENGTH; i++) {
        std::cout << std::hex << std::setw(2) << std::setfill('0') << (int)hash[i];
    }
    std::cout << std::endl;
    return 0;
}