Re: ptrdiff_t misuse

[Paul Eggert]

On 07/06/2012 08:43 AM, Eli Zaretskii wrote:
>> But not every use of ptrdiff_t is for buffer and string positions.
>> > Bitmap table sizes, for example.
> Do they really need to be large?

In some cases yes -- certainly in the memory allocators.
Maybe in some cases not, but nobody has taken the time
to think about it, and in the meantime ptrdiff_t is safer.
Generally speaking, if an object can grow and its size
is not limited for other reasons to INT_MAX-or-less,
code should not use 'int' to count its size.

> What for? they span the same range of values.

Yes, that's the point -- if ptrdiff_t and EMACS_POS
would span the same range of values, why bother to
distinguish the two?  Whether a value is a
buffer position is usually clearly stated in the
variable name.