Hands-On System Programming with C++

The high_resolution_clock function

On most systems, high_resolution_clock{} and steady_clock{} are the same. In general, high_resolution_clock{} represents the highest-resolution clock available as a steady clock and, as shown in the following example, the result is the same with stead_clock{}:

#include <chrono>#include <iostream>#include <unistd.h>int main(){    using namespace std::chrono;    auto now1 = high_resolution_clock::now();    sleep(2);    auto now2 = high_resolution_clock::now();    std::cout << "time: " <<        duration_cast<seconds>(now2 - now1).count() << '\n';    std::cout << "time: " <<        duration_cast<milliseconds>(now2 - now1).count() << '\n';    std::cout << "time: " <<        duration_cast<nanoseconds>(now2 - now1).count() << '\n';}// > g++ -std=c++17 ...