Re: Promoting unsigned long int to long int

pereges <Broli00@xxxxxxxxx> writes:
btw, i see a lot of people saying that size_t must be used over
unsigned long. The question is are there any fix guidelines as to when
i should and when i shouldn't use size_t. It seems to me that size_t
is most commonly used in three situations :

1. Size of array or any object.
2. Array indices.
3. Count of something.

Although I don't see why using unsigned long for any of the above
could be wrong. It may not be a necessity to use size_t

size_t can represent the size in bytes of any object (since it's the
type of the result of the sizeof operator and of the argument to
malloc(). It can therefore represent the size in elements of any
array object, making it suitable for array indices.

The third is a bit more iffy; it depends on what you're counting.

But there are no such guarantees for unsigned long. Consider a
hypothetical system where unsigned long is 32 bits and size_t is 64
bits. You might have objects whose size cannnot be represented as an
unsigned long value.

The question is, why would you want to use unsigned long rather than
size_t?

--
Keith Thompson (The_Other_Keith) kst-u@xxxxxxx <http://www.ghoti.net/~kst>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
.

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