Re: Integral types and own type definitions (was Re: Suggested method for returning a string from a C program?)

On 3/26/25 10:59, Janis Papanagnou wrote:

On 26.03.2025 12:33, David Brown wrote:

...

Even in C (in a desperate attempt to bring us back on topic for the
group), there are no negative integer constants - merely positive
integer constants with a unary minus operator applied.

 
Is that so? (Harmlessly asking.) - I mean, if I write  int x = -5;
does it matter (in "C") whether its parsed as  <integer number>  or
 <negation> <positive number> ?

It does make a difference in some contexts, but not in that one.

The problem I remember best is that if, for instance, the minimum
integer that can be represented by an int has the value -32768, then the
integer literal 32768 represents a value too big to be represented as an
integer, so it has the type 'long int' rather than 'int'. As result,
since the expression -32768 is parsed as the unary - operator applied to
32768, that expression also has the type 'long int'. That makes it
unsuitable as the #definition of INT_MIN. A popular alternative is to
#define INT_MIN as (-32767-1).
The same issue applies to INT_MIN regardless of what value it has, I
chose 16 bits only to reduce typing.