test.cpp

#include <array>
#include <iostream>
#include <stdio.h>
#include <chrono>

enum class Ax { X = 0, Y = 1, Z = 2 };

static constexpr std::array<Ax, 3> AXES = {Ax::X, Ax::Y, Ax::Z};

static constexpr auto COUNT = 200000000;


void experiment1() {
    int res = 0;
    auto start = std::chrono::steady_clock::now();
    for (size_t i = 0; i < COUNT; ++i) {
        for (auto ax : AXES) {
            res += static_cast<int>(i);
        }
    }
    auto end = std::chrono::steady_clock::now();
    std::cerr
        << std::chrono::duration_cast<std::chrono::milliseconds>(
            end - start).count() << std::endl;
}

void experiment2() {
    int res = 0;
    auto start = std::chrono::steady_clock::now();
    for (size_t i = 0; i < COUNT; ++i) {
        for (int j = 0; j < 3; ++j) {
            res += j;
        }
    }
    auto end = std::chrono::steady_clock::now();
    std::cerr
        << std::chrono::duration_cast<std::chrono::milliseconds>(
            end - start).count() << std::endl;
}

int main(int argc, char const *argv[])
{
    experiment1();
    experiment2();

    return 0;
}