FizzBuzz State Machine (C++)

fizzbuzz.cpp

/* 
   (Dumb) idea to implement the classic FizzBuzz
   problem as a state machine with 16 states.
*/

#include <iostream>
#include <vector>
#include <functional>
#include <stdlib.h>

#define HALT_AT 100

typedef std::function<int(int)> State;

State stateBuilder(auto func) {
	return [=](int i) -> int {
		// Perform the action of the state
		std::cout << func(i) << std::endl;
		
		// Transition state
		if (i >= HALT_AT) return 0;
		return i % 15 + 1;
	};
}

#define MAKE_STATE(x) stateBuilder([](int i) { return (x); })

State itos = MAKE_STATE(std::to_string(i));
State fizz = MAKE_STATE("Fizz");
State buzz = MAKE_STATE("Buzz");
State fzbz = MAKE_STATE("FizzBuzz");
State halt = [](auto) -> int { exit(0); };


int main() {
	// Create and program our state machine
	std::vector<State> machine(0x10, itos);

	machine[0x3] = machine[0x6] = machine[0x9] = machine[0xC] = fizz;
	machine[0x5] = machine[0xA] = buzz;
	machine[0xF] = fzbz;
	machine[0x0] = halt;
	
	// Run the state machine
	int i = 1, state = 1;
	while(state) {
		state = machine[state](i++);
	}

	return 0;
}

Sketch of the state machine:

I love this.