It can be a serious bug if it overflows and you didn't intend it to happen or you expected overflow behavior to do something different. But that's also true of

It can be a serious bug if it overflows and you didn't intend it to happen or you expected overflow behavior to do something different. But that's also true of `int c = a*b`, and yet that's not a compiler error. int/short should be thought of as storage size optimizations for memory. They're very bad ways to specify the correct range of values for a variable. (Ada has explicitly ranged integers though!)