[libcxx-commits] [libcxx] [libc++] Re-introduce special support for narrowing conversions to bool in variant (PR #73121)

[David Benjamin via libcxx-commits]

davidben wrote:

> Basically most people in the wild will see their code go from *p0608r3* to *p1957r2*, which seems like it wouldn't cause a lot of issues.

That's right. I should say, this is more by absence of evidence than anything else. The big internal Google repository is on *mostly-pre-p0608r3*, so no data from that. Chromium (where I spend my time) is also no data because it's currently on *pre-p0608r3* by way of `absl::variant`. I'm planning to take it straight to *p1957r2*. There weren't as many narrowing cases to fix, and there was one call site that was sensitive to the `vector<bool>` issue.

But given that GCC implemented p1957r2 in [2020](https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=c98fc4eb3afeda6ad8220d0d79bc1247a92c7c65) seemingly with no problems, hopefully it's fine?

https://github.com/llvm/llvm-project/pull/73121