> It is too slow.

What compiler? LLVM's codegen for extended integers is pretty good.
Extended power of two integers are relatively trivial. I wouldn't
expect some specific modular integer type to be able to do any better.

Jeremy

On Tue, Jan 13, 2026 at 7:43 AM Hans Åberg via Std-Proposals
<std-proposals_at_[hidden]> wrote:
>
>
> > On 13 Jan 2026, at 14:41, David Brown <david.brown_at_[hidden]> wrote:
> >
> > On 13/01/2026 14:34, Hans Åberg via Std-Proposals wrote:
> >> There might be support for modular integers int_mod<m> ≔ ℤ/mℤ for a modulus m that fits into a fixed-sized word, say 4096 bits for use in cryptology, m ≤ 2⁴⁰⁹⁶. With recursive templates, like those I have written, for fixed-size unsigned integral types up to uint4096_t, it should not be difficult to implement.
> >
> > "unsigned _BitInt(4096)" will give you that. That is already part of C23, and I believe it is coming to C++, though I don't know the current status off-hand.
>
> It is too slow.
>
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