className : virtual public anotherClassName ?

[serkan sendur]

i have seen an inheritance statement like this

className : virtual public anotherClassName

what does virtual mean there?

[ShawnCplus]

It's to solve the diamond inheritance problem where you have a base class, then 2 child classes then a 4th class that inherits from both of the previous classes. If the base class declares a function then there is ambiguity of that function in the 4th class. Declaring the 2 child classes as inheriting virtually will allow the implementation of the base class's to fall through to the 4th class.

[ArkM]

See, for example: http://en.wikipedia.org/wiki/Virtual_inheritance
So class className is a suitable player for "diamond" inheritance.

[ShawnCplus]

See, for example: http://en.wikipedia.org/wiki/Virtual_inheritance
So class className is a suitable player for "diamond" inheritance.

Yeah, that's a bit easier to follow than what I said but essentially the same :)

[serkan sendur]

thank you guys i have read it before, but this is the first time i see it in action.

[serkan sendur]

being able to inherit from more than one classes does not seem to be useful, that might be why it is not possible in C# or JAVA

[ShawnCplus]

being able to inherit from more than one classes does not seem to be useful, that might be why it is not possible in C# or JAVA

Heh, that's a whole 'nother thread to talk about the benefits, caveats and downfalls of multiple inheritance. Suffice it to say that it's definitely a bonus that C++ has it (sometimes)

[ArkM]

being able to inherit from more than one classes does not seem to be useful, that might be why it is not possible in C# or JAVA

Well, Money == Evil, that's why there are lots of paupers in the World ;)...

[serkan sendur]

Well, Money == Evil, that's why there are lots of paupers in the World ;)...

i didnt get it :( (probably language deficiency)