Re: "A diagram of C23 basic types"

On 09/04/2025 09:20, Michael S wrote:

On Tue, 8 Apr 2025 16:47:07 +0100
bart <bc@freeuk.com> wrote:
 

On 08/04/2025 15:57, David Brown wrote:

On 08/04/2025 15:32, bart wrote:

On 05/04/2025 18:56, Philipp Klaus Krause wrote:

Am 02.04.25 um 11:57 schrieb bart:

* Where are the fixed-width types from stdint.h?

>
Same as for size_t, etc: They don't exist. Those are not separate
types, just typedefs to some other types. E.g. uint16_t could be
typedef'ed to unsigned int.
 

>
This is the point I made a few weeks back, but others insisted
they were part of C:
>
>
Me:
  >> stdint.h et al are just ungainly bolt-ons, not fully supported
by the >> language.
>
Keith Thompson:
    > No, they're fully supported by the language.  They've been in
the ISO > standard since 1999.
  >
>
This is an exchange posted on 20-Mar-2025 at 19:10 GMT (header
shows 'Thu, 20 Mar 2025 12:10:22 -0700')
>
Clearly, they're not quite as fully supported as short, int etc;
they are usually just aliases. But that needn't stop them being
shown on such a chart.

>
Standard aliases are part of the language standard, and therefore
standard and fully supported parts of the language.
  

>
So, should they have been on that chart?
>
  > and fully supported parts of the language.
>
Differences between 'unsigned long long int' and 'uint64_t' up to C23:
>
                           uint64_t   unsigned long long int
>
Works without header     No         Yes
>
Literal suffix           No         Yes (ULL etc)
>
Dedicated printf format  No         Yes (%llu)
>
Dedicated scanf format   No         Yes (whatever that might be)
>
sizeof() might not be 8  No         Maybe

 I don't think that 'No' above is correct.
Take, for example, ADI SHARC DSPs. Traditionally, sizeof(uint64_t) was
2.
I looked into the latest manual and see that now their compiler have
an option -char-size-8 and with this option sizeof(uint64_t)=8. But
this option is available only for those members of SHARC family that
have HW support for byte addressing. Even for those, -char-size-8 is
not a default.

There was a stipulation for an 8-bit 'char' type, but it got lost. Maybe I deleted it and intended to have it as a note later on.
But better here would be whether the width (sizeof*CHAR_BIT) could be over 64 bits.

>
Reserved word[1]         No         Yes
>
Outside lexical scope[2] No         Yes
>
Incompatible with
   unsigned long int       No         Yes
>

 I don't understand why you say 'No'. AFAIK, on all existing systems
except 64-bit Unixen the answer is 'Yes'.

That last one was an oversight which I only spotted after posting (in Reddit you can edit your posts!).
The No should be Maybe.