Re: What is your opinion about unsigned int u = -2 ?

On 01/08/2024 08:02, Ben Bacarisse wrote:

Blue-Maned_Hawk <bluemanedhawk@invalid.invalid> writes:
 

Thiago Adams wrote:

...

How about this one?
>
unsigned int u2 = -2;
Does it makes sense? Maybe a warning here?

>
I cannot think of any situations where that would make sense, but i also
cannot guarantee that there are not any.

 Some of the multi-byte conversion functions (like mbrtowc) return either
(size_t)-1 or (size_t)-2 to indicate different kinds of failure so it's
not inconceivable that someone might write
   size_t processed_but_incomplete = -2;
 

I also notice that overflow is not an error for unsigned .
For instance:
unsigned long long a = ULLONG_MAX + ULLONG_MAX;
But it is for signed
long long a = LLONG_MAX + LLONG_MAX;
So it seams that anything is ok for unsigned but not for signed.
Maybe because all computer gave same answer for unsigned but this is not true for signed?