Overloading/Inheritance issue

[Sean Kelly]

Walter Bright wrote:
> Sean Kelly wrote:
>> Walter Bright wrote:
>>> I agree that this example is a problem. There's no way to detect it 
>>> at compile time, so it should throw a runtime exception. The way to 
>>> accomplish that is to stuff D's vtbl[] entry for B.set(int) with a 
>>> dummy function that throws the exception.
>>
>> Certain C++ compilers have done something like this in the past, if I 
>> remember correctly.  I'd have to do some googling to remember the 
>> details, but I'm sure it was either the MS or Sun compiler.
> 
> I didn't know that. This particular problem may not come up so often 
> with C++ because functions are not virtual by default - but not virtual 
> by default produces its own set of very hard to find bugs that I've 
> wasted many hours tracking down.

I stumbled across the information while trying to diagnose a bizarre 
linker error.  It turned out that the function that couldn't be found 
was the dummy routine.  And that reminds me which compiler it is--it's 
the MS one.  Their explanation made it seem like the situation the 
routine was there for wasn't likely to ever actually happen and I 
regarded it as a curiosity at the time.  It's kind of neat to see the 
idea resurface here though :-)


Sean