How do I prevent my 'unused' global variables being compiled out?

Question

I\'m using static initialisation to ease the process of registering some classes with a factory in C++. Unfortunately, I think the compiler is optimising out the \'unused\'

Answer 1

To build off of Arthur Ulfeldt, volatile tells the compiler that this variable can change outside of the knowledge of the compiler. I've used it for put a statement to allow the debugger to set a breakpoint. It's also useful for hardware registers that can change based on the environment or that need a special sequence. i.e. Serial Port receive register and certain watchdog registers.