Resolution Measurement `std :: clock ()`

Question

Can std::clock() call resolution be measured? Or is it a problem when observation without influence is impossible?

I wrote the following naive landmark:

 #include <ctime> #include <iostream> int main() { std::clock_t initial = std::clock(); std::clock_t current; while (initial == (current = std::clock())); std::cout << "Initial: " << initial << std::endl; std::cout << "Current: " << current << std::endl; std::cout << "Precision: " << (static_cast<double>(current - initial) / CLOCKS_PER_SEC) << "s" << std::endl; } 

I ran it a few hundred times and it always outputs 0.01s .

My questions:

• Is code above a good way to measure clock() resolution?
• If not, then what's wrong with that? And how can this be improved?

Answer 1

You can, kind of. Something like what you are doing, ok first approximation. But I'm not sure how useful it is: it determines but it still does not say anything about accuracy; under Windows, for example, clock so inaccurate that displaying it is useless.