[libcxx-commits] [libcxx] [libc++] P1789R3: Library Support for Expansion Statements (PR #167184)

[Matthias Wippich via libcxx-commits]

Tsche wrote:

> > > Thank your for working on this. I think it is possible also to add a functional test too to demonstrate the feature?.
> > 
> > 
> > Unfortunately not at this time. To properly showcase the structured binding use-case we need P2686, for the expansion statement one we need P1306. From what I can tell clang currently supports neither.
> 
> I think it's still worthwhile testing "plain" (non-`constexpr`) structured bindings and structured binding packs.

It turns out P2686 is partially implemented. We do not yet seem to be able to retrieve values in a constant evaluated expression, so I'm using plain `assert` for now. I left a note.

https://github.com/llvm/llvm-project/pull/167184