[libcxx-commits] [PATCH] D157058: [libc++] Remove generic char_traits implementation

[Reid Kleckner via Phabricator via libcxx-commits]

rnk added subscribers: cjdb, rnk.
rnk added a comment.

> FWIW after speaking with @thakis offline, I do think we did "everything right", in the following sense. We added the deprecated attribute to the class and left it there across one full release (roughly 1 year). This should leave enough time for people to notice the warning when updating libc++, turn it off temporarily with -Wno-deprecated as they fix their code, and then re-enable the warning. I think this is the right model we want to give folks.

I think this gets to some recent Clang discussions <https://discourse.llvm.org/t/exposing-the-diagnostic-engine-to-c/73092/1> about adding library diagnostics. After you fix the system header problem, the next problem is that we have one giant `-Wdeprecated-declarations` flag, and in a sufficiently large codebase, it only takes a few deprecation attributes in code you don't control before you have to disable this warning globally. We have users who build with `-Wno-deprecated-declarations`, and it's not reasonable to say "oh, you turned off the warnings, so it's your own fault you missed the deprecation period". We need a solution for finer grained deprecation warnings, -Wdeprecated=libcxx, -Wdeprecated=char_traits, or a better spelling.

@cjdb , is there a github issue that folks can watch to get updates on this proposal?


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  https://reviews.llvm.org/D157058/new/

https://reviews.llvm.org/D157058