For some reason it is rather difficult to obtain elapsed milliseconds in C++. You can use time(), but that only has a resolution of 1 second. You can use clock() but then I/O operations which do not use clock cycles will report an ellapsed time of 0. Furthermore this is OS dependent. Consider the following example:
std::clock_t tick = std::clock();
// Wait for user input.
std::string input;
std::cin >> input;
std::clock_t now = std::clock();
int milliseconds = float(now - tick) / CLOCKS_PER_SEC * 1000; On Windows this example will work as intended, and milliseconds will hold the
number of milliseconds spent waiting for user input. However in Linux and OS X
IO operations do not use clock cycles and milliseconds will be near 0.
BasicTimer provides a portable solution using the timeb struct and ftime.
Unlike the previous example, the example below will work as intended and report
the number of milliseconds spent waiting for user input.
BasicTimer timer;
timer.tick();
// Wait for user input.
std::string input;
std::cin >> input;
int milliseconds = timer.millisecondsSinceTick();