Re: A: a new bug to old plain C

Den sön 7 dec. 2025 kl 23:46 skrev Segher Boessenkool <
[email protected]>:

> On Sun, Dec 07, 2025 at 01:49:46PM -0800, Andrey Tarasevich wrote:
> > > > There are lots and lots of
> > > > conversions in C that are only available through _explicit_ _casts_
> > >
> > > Where "lots and lots" means "exactly zero": you can always do an
> > > ssignment to something with an appropriate type.
> >
> > I'm not sure what you are trying to say here. Constraints of assignment
> in C are exactly
> > as strict as constraints of initialization. (In fact, the later are
> defined in the standard
> > simply by a direct reference to the former.)
>
> I am saying that explicit casts (which means using a cast operator) are
> never ever required.
>

yes they are:

int main (int argc, char **argv)
{
  struct a a;
  struct b b = a;

test.c: In function ‘main’:
test.c:1308:22: error: invalid initializer
 1308 |         struct b b = a;

/HH

>
> And no, you never have to go via pointer stuff either.  Just assign to
> something that actually holds the type you are trying to convert to.
> Don't hide aything!  It won't help you!
>
>
> Segher
>