May I ask your opinion why std:: and your concepts are basically a fancy
type lists and not something more abstract?
For example for std::floating_point I would expect certain operations like
construction addition, division work “as expected” so that any 3rd party
type is matched.
I presume the issue is agreeing what a “as expected” is so std:: picked
easier type list approach.

On Sat, 12 Apr 2025 at 19:08, Howard Hinnant via Std-Proposals <
std-proposals_at_[hidden]> wrote:

> Ancedote:
>
> std::integral recently fell out of favor with me and I wrote my own
> concept that better suited my needs:
>
> https://github.com/HowardHinnant/bbi/blob/master/bbi.h#L176-L191
>
> StandardSignedInteger
> StandardUnsignedInteger
> StandardInteger
>
> The difference here is that my concepts exclue bool and the character
> types. This distinction was at best not clear in C++11, and not modeled by
> the type_traits introduced then. For my work today, it is important to not
> include bool and the character types as “integral types” as their semantics
> are not consistent with the representaiton of integral numbers.
>
> I mention this ancedote as a word of caution for building further concepts
> on top of type_traits. type_traits was a good model of the type system
> when they were introduced, but may not be today, 15 years later.
>
> Howard
>
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>