naming convention for methods that transfer ownership

Question

Consider the following example:

class Foo
{
    private Bar x;

    // ...

    public Bar getAndResetX()
    {
        Bar result = x;
        x = new Bar();
        return result;
    }
}

Is there an established naming conventions for such methods? Like yieldX, transferX or something?

Answer 1

We used to have the convention Adopt and Orphan as a prefix to provide intention in the method name (taken from Taligent book on C++).

Bar b = foo.orphanBar(); // take Bar out of Foo
foo.adoptBar(b); // put it right back in

You could use something similar to provide ownership clues to the objects. Quite frankly though I would stick with the Java convention of using add and remove. They provide enough intention and other programmers will not need to read a comment explaining the new convention.

Bar b = foo.removeBar(); // take Bar out of Foo
foo.addBar(b); // put it right back in

Answer 2

I'm not sure that there is a naming convention for such methods. IMHO, I would use the verb take (e.g. takeX()). For more information regarding method naming conventions, see JLS §6.8.3 Method Names.

But in all honesty, it's really just a matter of opinion. If you're really that concerned, I'd recommend you browse the Java API for methods that are functionally equivalent, and then model your method name after those.

Answer 3

Mozilla's native smart-pointer classes use the method forget() to indicate a transfer of ownership:

already_AddRefed<nsIFoo> GetFoo() {
    nsCOMPtr<nsIFoo> foo = ...
    ...
    return foo.forget();
}