Re: Promoting unsigned long int to long int

On Jun 30, 11:19 pm, santosh <santosh....@xxxxxxxxx> wrote:

1. Size of array or any object.

This is the purpose of size_t.

2. Array indices.

IMHO, any unsigned type of suitable range will do. Sometimes signed
types are convenient too, for certain forms of loops, and rarely, to
index with a negative offset.

3. Count of something.

Again a suitable unsigned type, not necessarily size_t should be okay.

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

You are correct. In C, size_t has the only purpose of being large enough
to hold the size in bytes of the largest possible single object. Also
the sizeof operator yields a size_t value for related reasons. It is
not necessarily a suitable type for counting things are holding
offsets, indexes and such.

Generally, a careful examination of the origin, purpose and types of use
a value may be subject to will give you a clue as to the most suitable
type of object to represent it.

Thanks for the clarification. After reading this, I guess I will
continue using unsigned long for all the 3 situations.
.

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