Function Return Types

Up till now we have only returned built-in types by value. As we saw in the class on strings, user-defined types can also be returned by value. So the questions are

1. Can you return a built-in type or user-defined type by "const value" and if so, does it make sense?
   Yes; almost never

2. Can you return a built-in type or user-defined type by reference and if so, does it make sense?
   Yes; sometimes but there are pitfalls. We do this often when we are returning a reference to a parameter that was passed in by reference. Checkout this code which illustrates one of the pitfalls and (hopefully) results in a compiler error or warning. int& AddOne ( int n ) { int x = n + 1; return x; }

3. Can you return a built-in type or user-defined types by reference to const and if so, does it make sense?
   Yes; sometimes but the same pitfalls exists.