How to get duration, as int milli's and float seconds from <chrono>?

Question

I'm trying to use chrono library for timers and durations.

I want to be able to have a Duration frameStart; ( from app start ) and a Duration frameDelta; ( time between frames )

I need to be able to get the frameDelta duration as milliseconds and float seconds.

How do you do this with the new c++11 <chrono> libraries? I've been working on it and googling ( information is sparse ). The code is heavily templated and requires special casts and things, I can't figure out how to use this library correctly.

Answer 1

Is this what you're looking for?

#include <chrono>
#include <iostream>

int main()
{
    typedef std::chrono::high_resolution_clock Time;
    typedef std::chrono::milliseconds ms;
    typedef std::chrono::duration<float> fsec;
    auto t0 = Time::now();
    auto t1 = Time::now();
    fsec fs = t1 - t0;
    ms d = std::chrono::duration_cast<ms>(fs);
    std::cout << fs.count() << "s\n";
    std::cout << d.count() << "ms\n";
}

which for me prints out:

6.5e-08s
0ms