Apply C style string in switch-case clause in C++. (C++11 or above required)

cstring_switch.cc

#include <iostream>
#include <string>

using hash_t = size_t;
constexpr hash_t prime = 0x100000001B3ull;
constexpr hash_t basis = 0xCBF29CE484222325ull;

hash_t hash_run_time(const char* str) {
    hash_t ret = basis;

    while (*str) {
        ret ^= *str;
        ret *= prime;
        str++;
    }

    return ret;
}

constexpr hash_t hash_compile_time(const char* str, hash_t last_value = basis) {
    return *str ? hash_compile_time(str + 1, (*str ^ last_value) * prime) : last_value;
}

constexpr hash_t operator "" _hash(const char* p, size_t) {
    return hash_compile_time(p);
}

void simple_switch(const char* str) {
    switch (hash_run_time(str)) {
        case "first"_hash:
            std::cout << "1st" << std::endl;
            break;
        case "second"_hash:
            std::cout << "2nd" << std::endl;
            break;
        case "third"_hash:
            std::cout << "3rd" << std::endl;
            break;
        default:
            std::cout << "Default..." << std::endl;
    }
}

int main() {
    std::string str = "first";
    simple_switch(str.c_str());

    simple_switch("second");

    str = "third";
    simple_switch(str.c_str());

    simple_switch("default");

    return 0;
}