aliasing base methods

[Bill Baxter]

Frank Benoit (keinfarbton) wrote:
>> class Base
>> {
>>    int foo(int) { ... }
>> }
>> class Derived : Base
>> {
>>    // Is this "error: override keyword required"
>>    // Or is it ok -- not an override but a distict overload leaving
>>    // foo(int) in tact.
>>    int foo(float) { ... }
>> }
>>
> 
> In this case it would compile without error. You did not provide
> 'override', so you say: make overload.
> 
> If 'override' is required, it would be obvious, that it is missing. 

I'm not so sure.  I try to live by the 'mark all overrides' policy 
myself but still I often forget.

> So I
> think it would be much easier to find this error (if override was
> meant). And it is documented for a later reader. This is an improvement
> of readability.

Any improvement of readability comes from 2) -- making 'override' 
required.  Not from 1) -- making all overloads propagate.  1) saves 
typing but does not necessarily improve readability.  What could be more 
clear than an explicit list of all the base class versions of foo()?

Also -- does this() get special treatment?  Or do constructors all 
automatically propagate too?

And in general how do I hide super.foo(int) if I _don't_ want it? 
(private assert(0) re-implementation of every method I don't want perhaps?)

I guess I would be happier with something that required explicitly 
declaring that base class overloads should be forwarded.  Like
    alias super.foo foo;  // bring forward all base class foo's
or
    alias super.foo(int) foo; // bring forward only the int version.


Another thought -- making override required could make life difficult 
for some code generators.  Imagine an automatic class wrapper that 
creates a derived class of the form:

class foo(Base)  : Base
{
    int someMethod(int x) { ... }
}

That will always work now, but if override becomes required, then that 
template will have to do some static if mojo to figure out if Base 
already has a someMethod(int) implemented or not and if so stick in the 
'override'.

--bb