On Thursday, 5 April 2018 at 19:31:39 UTC, Jonathan M Davis wrote:
And you can't abstract whether a member variable is marked with immutable or not. That's part of the variable. Declaring an immutable instance of an object would then treat the member variable in immutable for that instance, so it's possible to have an immutable member variable when the member variable is not itself marked with immutable, but class inheritance has nothing to do with controlling which type qualifiers were used on the member variable of a base class. Derived classes override member functions. They don't override member variables or anything about them. They override the behavior of the base class, not the structure.
That beats my argumentation. Fully agree with that.
For them to do otherwise would become quite problematic if you ever use a derived class through a base class reference. They can add onto the structure of a base class, but the derived class must be usuable via a base class reference, and trying to do something like have the derived class alter the qualifiers on base class member variable simply would not work with that. That sort of thing could only ever work if the base class were just a way to add functionality to a derived class rather than having anything to do with references, and that's simply not how classes work in D. If that's the sort of thing that you want, it would make more sense to add the functionality via composition rather than inheritance.
Yeah... little bit of mixing things up in my head, maybe... Did exactly this stuff during the last couple of months.
Thanks a lot!
