On: The Dawn of Haiku OS

[pjmlp]

The problem is not C++ specific.

Any OO language with native code generation suffers the same problem.

It is one of the consequences of the fragile base class problem in OO.

[astrange → pjmlp]

Objective-C 64bit ABI doesn't have fragile base classes; there's an extra layer of indirection to access any data member of an object.

And it actually has private data members! Isn't that nice.

(Private meaning they aren't declared in the public headers, not meaning it uses the useless 'private' attribute.)

[pjmlp → astrange]

Yes it does, as any OO language does.

This is not only about data member access. It also applies to adding methods on the base class that change the behavior of existing methods in already declared subclasses.

Take a cup of coffee and read this famous paper about the issue,

http://www.cas.mcmaster.ca/~emil/Publications_files/Mikhajlo...