[PATCH] D55466: Change `tuple_size` from a `class` to a `struct` (see PR#39871)

[Marshall Clow via Phabricator]

mclow.lists added a comment.

I'm waiting for the (editorial) change to go into the standard; once that happens, I will commit this.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D55466/new/

https://reviews.llvm.org/D55466