Thread: How to add times elapsed from function inside a loop?

I have implemented two ways of doing something inside a loop. I'd like to time them to find out which to keep.

Code:

for(int i = 0; i < 1000; i++)
{
    int x = whatever(i);
    foo1(x);
    foo2(x)
}

How can I find out the total time of foo1 and foo2? I tried declaring an std::chrono variable outside the for loop and measuring foo1 and food2 with now() but times elapsed can't be added.