Avi Kivity

I think the rules for plain-old-data unions are more relaxed.

"If two union members are [standard-layout](https://en.cppreference.com/w/cpp/named_req/StandardLayoutType) types, it's well-defined to examine their common subsequence on any compiler." I don't know if it counts as a subsequence since size is at...

If size is moved out of the union, then the small-string case fits smaller strings (by 7 chars).

Very harmful. Right now sstring takes 16 bytes. We don't want to bloat it.

This is not a seastar issue, but rather a scylla issue due to its use of wasmtime which installs signal handlers.

"preserve the value category" means future::then should behave differently depending on the value category of its parameter (i.e. also remember if it was passed an ordinary reference). I think that's...

I think restricting to rvalues makes the most sense (and by restricting, I mean having a deprecation period where lvalues still "work", but emit a warning). By far the most...

We should keep doing what we do now to avoid breaking code.

About which operator() should we call - I don't have an intuition. I suppose calling operator()(...) && will decay to operator()(...) & or operator()(...) const & if just those are...

Fixes ...? If it triggers a Scylla bug, please reference.