Should I use "int" or "bool" as a return value in C++?

Question

If I have a function that performs some procedure and then needs to return the truth value of something is there a compelling reason to use either a boolean variable, or an int variable, as the return type?

bool Foo()
{
  ...
  ...
  return truthValue;
}

int Foo()
{
  ...
  ...
  return truthValue;
}

Is there an appreciable difference between these two functions? What are some potential pitfalls and advantages to both of them?

thanks,

nmr

Answer 1

If it's a genuine truth value, then you should use a bool as it makes it very clear to the caller what will be returned. When returning an int, it could be seen as a code/enum type value.

Code should be as clear and explicit as possible whether it be function names, parameter names and types, as well as the types of the return codes. This provides more self-documenting code, code that is easier to maintain, and a lower probability that someone will misinterpret what you "meant".

Answer 2

If you want to return a binary truth value then you should be using a boolean data type where available.

Compilers will optimise things if necessary, you should be writing your code as much as possible to be clear. That way, you or your successor will have no doubt five years down the track what was intended.