#include <iostream>
#include <chrono>
 
int main() {
unsigned long begin_time = \
    std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now().time_since_epoch()).count();
 
//some code here
 
std::cout << "time diff with arithmetic in cout: " << \
    std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now().time_since_epoch()).count() - begin_time << std::endl;
 
unsigned long time_diff = \
    std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now().time_since_epoch()).count() - begin_time;
 
std::cout << "time_diff: " << time_diff << std::endl;
}

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