[libcxx-commits] [PATCH] D101206: [libc++] Remove UB in std::list

[Arthur O'Dwyer via Phabricator via libcxx-commits]

Quuxplusone added reviewers: ldionne, EricWF, Quuxplusone, Mordante.
Quuxplusone added a comment.

@Mordante: yes it does. :)
@akhuang: My understanding is that removing-the-UB is needed (or at least desired) for the benefit of some particular sanitizer; could you add info to the review summary (and commit message) about that?
Also, are we really interested in getting that benefit for C++03 code?  Arguably it would be better to preserve the existing behavior for C++03 and fix the behavior only for C++>=11. Is it physically possible to go that route? and if so, does that eliminate a lot of the ifdefs in this PR? (I'm thinking we could just have one ifdef around the `union` itself, and then the rest of the code wouldn't need ifdefs at all.) The behavior would remain UB, but unchanged, in C++03; and we could say "if you want to use such-and-such sanitizer, please compile as C++>=11." That won't be a hardship for the user, will it?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D101206/new/

https://reviews.llvm.org/D101206