What you are asking for is the Y combinator. Apparently there was a
proposal to add it to the standard library (
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0200r0.html) but
I don't know what happened to it.

On Fri, May 16, 2025 at 1:59 AM Frederick Virchanza Gotham via
Std-Proposals <std-proposals_at_[hidden]> wrote:

> On Thu, May 15, 2025 at 2:16 PM Pavel Vazharov wrote:
> >
> > C++23 is enough to cover you here:
> >
> > #include <print>
> >
> > int main(int const argc, char **const argv)
> > {
> > auto func = [argv](this auto&& self, int count)
> > {
> > if ( 0 == count ) return;
> > std::println("{}", argv[count - 1]);
> > self(count - 1);
> > };
> > func(argc);
> > }
>
>
> int main(int const argc, char **const argv)
> {
> auto func1 = +[](int count, char **argv)
> {
> // This one cannot recurse
> };
>
> auto func2 = +[](this auto &&self, int count, char **argv)
> {
> // This one won't compile
> };
> }
>
> Normally if a lambda doesn't have any captures, you can turn it into a
> normal function pointer by using the unary '+' operator. However in
> your code example, the lambda cannot be turned into a normal function
> pointer -- because it needs to be invoked on an object (i.e. it needs
> the 'this' pointer).
>
> So we still don't have a 'perfect' solution here yet, not even with
> C++23. I think for perfection we'd need std::recurse.
> --
> Std-Proposals mailing list
> Std-Proposals_at_[hidden]
> https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
>

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