Add macro to notify user if debug mode is on?

[emilydolson]

I'm not sure what balance between keeping the default files simple and adding useful features you want to strike, but it just occurred to me that you could make it clear when debug mode is on by add the following to main():

#ifndef NDEBUG
std::cout << "Running in debug mode << std::endl;
#endif

This idea brought to you be the fact that I just spent 20 minutes timing a run of a program and then realized I wasn't sure whether I compiled with debug mode on or off 😄