Re: type based aliasing again

["Martin v. Loewis" <martin at mira dot isdn dot cs dot tu-berlin dot de>]

> Careful.  Are you sure that ANSI says that we can't call this an error?
> Is the language describing the type rules for accesses distinct from
> other language like
> 
> 	const int foo = 3;
> 	if (0) {
> 		foo = 4;
> 	}
> 
> ?  It's illegal to assign to a const, but here we are not assigning to
> a const, because the code is unreachable.

There's a difference between ill-formed code (which typically must be
diagnosed), and code exhibiting undefined behaviour. Your example is
of the former category; the aliasing stuff is of the latter.

Of course, the compiler may produce warnings which are not
diagnostics; it must still accept a well-formed program afterwards.

Regards,
Martin