Question

Take a look at this code:

Foo &Bar::Copy()
{
    return Bar();
}

The class Bar is inherited from Foo, and Foo is an abstract class. But when I call Bar() and return it, is it safe to do so? Or would I be returning the address of a local variable that would be freed by the end of the Copy() function?

Advice is greatly appreciated!

Answer 1

When calling Bar(); you call constructor on an implicit temporary object to which reference is returned. If you intend to create a Clone() like function a typical solution is to create the clone on the heap with new. You may use a kind of smart pointer to simplify life cycle management. You may also apply covariant return type to avoid type conversions in some cases using signature: Bar &Bar::Copy()