Timer function to provide time in nano seconds using C++

Question

I wish to calculate the time it took for an API to return a value. The time taken for such an action is in the space of nano seconds. As the API is a C++ class/function, I a

Answer 1

If this is for Linux, I've been using the function "gettimeofday", which returns a struct that gives the seconds and microseconds since the Epoch. You can then use timersub to subtract the two to get the difference in time, and convert it to whatever precision of time you want. However, you specify nanoseconds, and it looks like the function clock_gettime() is what you're looking for. It puts the time in terms of seconds and nanoseconds into the structure you pass into it.