Re: "A diagram of C23 basic types"

On 02.04.2025 09:32, Kaz Kylheku wrote:

On 2025-04-02, Janis Papanagnou <janis_papanagnou+ng@hotmail.com> wrote:

On 02.04.2025 07:59, Alexis wrote:

>
Thought people here might be interested in this image on Jens Gustedt's
blog, which translates section 6.2.5, "Types", of the C23 standard
into a graph of inclusions:
>
  https://gustedt.wordpress.com/2025/03/29/a-diagram-of-c23-basic-types/

>
A nice overview. - I have questions on some of these types...
>
The _Decimal* types - are these just types with other implicit
encodings, say, BCD encoded, or some such?

 
IEEE 754 defines decimal floating point types now, so that's what
that is about. The spec allows for the significand to be encoded
using Binary Integer Decimal, or to use Densely Packed Decimal.

Thanks for the hint and keywords. It seems my BCD guess was not far
from what these two IEEE formats actually are.

Does that now mean that every conforming C23 compiler must support
yet more numeric types, including multiple implementation-versions
of the whole arithmetic functions and operators necessary?

I wonder why these variants had been introduced.

In many other languages you have abstractions of numeric types, not
every implicitly encoding variant revealed an the programming level.

Janis