std::chrono::high_resolution_clock::now - cppreference.com (original) (raw)

Returns a time point representing the current point in time.

[edit] Return value

A time point representing the current time.

[edit] Example

#include #include #include #include #include #include   volatile int sink; // prevents optimization   void do_some_work(std::size_t size) { std::vector v(size, 42); sink = std::accumulate(v.begin(), v.end(), 0); // ensures side effect }   int main() { std::cout << std::fixed << std::setprecision(9) << std::left; for (auto size{1ull}; size < 1000'000'000ull; size *= 100) { const auto start = std::chrono::high_resolution_clock::now(); do_some_work(size); const auto end = std::chrono::high_resolution_clock::now(); const std::chrono::duration diff = end - start; std::cout << "start = " << start << "; end = " << end << ";\n"; std::cout << "diff = " << diff << "; size = " << size << '\n'; } }

Possible output:

start = 2024-10-25 13:37:42.016233947; end = 2024-10-25 13:37:42.016239362; diff = 0.000005415s; size = 1 start = 2024-10-25 13:37:42.016384595; end = 2024-10-25 13:37:42.016386581; diff = 0.000001986s; size = 100 start = 2024-10-25 13:37:42.016394197; end = 2024-10-25 13:37:42.016445830; diff = 0.000051633s; size = 10000 start = 2024-10-25 13:37:42.016452737; end = 2024-10-25 13:37:42.022496657; diff = 0.006043920s; size = 1000000 start = 2024-10-25 13:37:42.022511298; end = 2024-10-25 13:37:42.658639946; diff = 0.636128648s; size = 100000000