Function print_timing

tests/BS_thread_pool_test.cpp:3134–3140

* @brief Print the timing of a specific test. * * @param stats A struct containing the mean and standard deviation. * @param pixels_per_ms The number of pixels per millisecond. */

 * @param pixels_per_ms The number of pixels per millisecond.
 */
void print_timing(const mean_sd& stats, const double pixels_per_ms)
{
    constexpr int width_mean = 6;
    constexpr int width_sd = 4;
    constexpr int width_pms = 7;
    logln("-> Mean: ", std::setw(width_mean), stats.mean, " ms, standard deviation: ", std::setw(width_sd), stats.sd, " ms, speed: ", std::setw(width_pms), pixels_per_ms, " pixels/ms.");
}

/**
 * @brief Find the index of the minimum element in a vector.