Get dt in milliseconds

Hey guys

I need to get the gametime in milliseconds for some code that I am working on.

I can get milliseconds like this:

@tieudaotu

The simplest way to get current time in milliseconds is:

auto timeInMillis = std::time(nullptr); //returns long type
Also do remember to include:

#include <time.h>

I got that from here: How to get current time in milliseconds?

But I would like to be able to get dt and milliseconds because I need it in another update function.