[mbed OS6] elapsed time

mbed_chrono.cpp

#include "mbed.h"

int main() {
    Timer t;
    t.start();
    ThisThread::sleep_for(1s);
    t.stop();
    auto f = chrono::duration<float>(t.elapsed_time()).count();
    auto s = chrono::duration_cast<chrono::seconds>(t.elapsed_time()).count();
    auto ms = chrono::duration_cast<chrono::milliseconds>(t.elapsed_time()).count();
    auto us = t.elapsed_time().count();
    printf ("Timer time: %f s\n", f);
    printf ("Timer time: %llu s\n", s);
    printf ("Timer time: %llu ms\n", ms);
    printf ("Timer time: %llu us\n", us);
}

// Timer time: 1.002245 s
// Timer time: 1 s
// Timer time: 1002 ms
// Timer time: 1002245 us