What does “warning: not all control paths return a value” mean? (C++)

Question

The exact warning I get is

warning C4715: \'hand::show\' : not all control paths return a value

and hand::show is

std::ostr         


        

Answer 1

Your compiler isn't smart enough to take into account that the only two options for side are left and right, so it thinks it's possible for neither return statement to be executed. When side is neither left nor right, your function doesn't say which value to return.