Re: ptrdiff_t misuse

[Dmitry Antipov]

On 07/06/2012 08:00 PM, Eli Zaretskii wrote:

> > Yes, that's the point -- if ptrdiff_t and EMACS_POS
> > would span the same range of values, why bother to
> > distinguish the two?
>
> Because Emacs positions are not pointers, nor differences between
> pointers.

IMHO you mix the confusing type name and it's real use.

I read ptrdiff_t exactly as "difference between pointers", and this is
the minor drawback; the major one is that there is no standard unsigned
counterpart, like for size_t/ssize_t pair.

> > Whether a value is a buffer position is usually clearly stated in
> > the variable name.
>
> I refer you to the recent repeated confusions about this by Dmitry.

This isn't related to any type (mis)use. In a struct window,
window_end_pos really means something like last_displayed_pos;
this is quite hard to mix with window_end_[whatever].

Dmitry