[antlr-interest] anybody get bitten by ANTLR's AST interface requirement

[Sohail Somani]

On Tue, 2006-01-24 at 10:59 +0100, Martin Probst wrote:
> In code:
> 
> class X { .. }
> class Y extends X { .. }
> 
> class A {
>   X foo();
> }
> 
> class B extends A {
>   Y foo(); // <-- !!!
> }
> 
> The class B with the overriding foo() returning Y was not possible
> before, and it can really enhance complicated APIs. E.g. if you move
> down the API abstraction level you can now have the more concrete
> classes also return more concrete types, and that is nice.

Yes, these are covariant returns types in C++. Thanks for clarifying!