Darren New <dne### [at] sanrrcom> wrote:
> >   Could you give a concrete example of a compiler, of any OO language,
> > which will only *warn* (rather than give an error message) if you try to
> > access a member variable specifically marked as private from the outside?

> Sure. C# or Java. You get this warning that says "this won't compile."

  Wait. The compiler gives a *warning* which says "this won't compile"?
If it's just a warning, and not an error, it means that it will compile
it anyways? Isn't that contradictory?

> Another example is, as I've been saying, C++. The compiler warns (and won't 
> compile) if you access the private variable by name

  I get no warning if I try to access a private member. I get an error.
There's a big categorical difference.

>, but not if you 
> intentionally or accidentally access the private variable by address.

  You can't access the private variable by address. Not according to the
standard. If you can, then that can be considered a non-standard compiler
extension.

  And trashing memory, triggering UB, is not the same thing as "accessing
a member variable". The effect may be the same as accessing in one compiler,
but might not be in another. You are not *really* accessing it. You are
just abusing compiler and system specific undefined behavior.

-- 
                                                          - Warp

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