While the idea is is worth pursuing, extensible math functions would be a
lot of design work that cuts horizontally across several proposals:

   - P3935R0 "Rebasing <cmath> on C23" adds many more mathematical
   functions.
   - P3045R7 "Quantities and units library" also mentions mathematical
   functions that operate on quantities.
   - I forgot the number ... we had a proposal that lets you explicitly
   specify rounding modes for math functions I believe.

I suspect that if we were to add quantities and units to the standard
library, then new mathematical functions will be part of that library in
some way. Being able to std::floor a second or meter or something is a
major motivating use case. You should get in touch with the authors and see
how much overlap there is.

On Wed, 1 Apr 2026 at 23:19, Stéphane Gros-Lemesre via Std-Proposals <
std-proposals_at_[hidden]> wrote:

> Hello,
> It is my first time posting here, I'm not sure I am following the proper
> process. Please let me know if I'm doing this wrong.
>
> I wanted to float here this idea, see if there would be interest.
> The idea is providing an extension mechanism for std math functions.
>
> The idea is presented here:
> https://github.com/StephaneGrosLemesre/ExtensibleMath
>
> Or in the attached pdf.
>
> Please let me know what you think,
> Kind regards,
> Stéphane
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