SFML - sf::Texture::loadFromFile test

#include <iostream>
#include <SFML/Graphics.hpp>
#include <chrono>


void load(std::string file, double& t) {
    sf::Texture tex;
    auto t1 = std::chrono::steady_clock::now();
    tex.loadFromFile("test.png");
    auto t2 = std::chrono::steady_clock::now();
    t = std::chrono::duration_cast<std::chrono::duration<double>>(t2-t1).count();
}
double mean(double a[], int size) {
    double tot = 0;
    for (int i = 0; i < size; i++) {
        tot += a[i];
    }
    return tot/(double)size;
}

int main() {
    // initializing
    const int no_tests = 20;
    double png[no_tests] = {0};
    double jpg[no_tests] = {0};
    double bmp[no_tests] = {0};

    // warm up the GPU
    std::cout << "Warming up...\n";
    {
        double dummy;
        load("test.png",dummy);
        load("test.jpg",dummy);
        load("test.bmp",dummy);
    }

    // do tests
    std::cout << "PNG test";
    for (int i = 0; i < no_tests; i++) {
        load("test.png", png[i]);
        std::cout << ".";
    }
    std::cout << "\n";

    std::cout << "JPG test";
    for (int i = 0; i < no_tests; i++) {
        load("test.jpg", jpg[i]);
        std::cout << ".";
    }
    std::cout << "\n";

    std::cout << "BMP test";
    for (int i = 0; i < no_tests; i++) {
        load("test.bmp", bmp[i]);
        std::cout << ".";
    }
    std::cout << "\n\n";

    // show results
    std::cout << "PNG time: " << mean(png,no_tests)*1000 << "ms\n";
    std::cout << "JPG time: " << mean(jpg,no_tests)*1000 << "ms\n";
    std::cout << "BMP time: " << mean(bmp,no_tests)*1000 << "ms\n";


    return 0;
}