How to get current timestamp in milliseconds since 1970 just the way Java gets

Question

In Java, we can use System.currentTimeMillis() to get the current timestamp in Milliseconds since epoch time which is -

the difference, m

Answer 1

Since C++11 you can use std::chrono:

• get current system time: std::chrono::system_clock::now()
• get time since epoch: .time_since_epoch()
• translate the underlying unit to milliseconds: duration_cast(d)
• translate std::chrono::milliseconds to integer (uint64_t to avoid overflow)

#include 
#include 
#include 

uint64_t timeSinceEpochMillisec() {
  using namespace std::chrono;
  return duration_cast(system_clock::now().time_since_epoch()).count();
}

int main() {
  std::cout << timeSinceEpochMillisec() << std::endl;
  return 0;
}