In C, int may be as small as 16 bits You may get 32 bits (or more) but it's not guaranteed. I don't see how you get a memory overflow though?

I'd be surprised if a compiler with -Wall -Werror accepts to compile this.

Trying to cast back the int to a char* might work if the pointers are the same size as int on the target platform, but it's actually Undefined Behaviour IIRC.