[PATCH] D27387: [libc++] Add a key function for bad_function_call

[Shoaib Meenai via Phabricator via cfe-commits]

smeenai added a comment.

In https://reviews.llvm.org/D27387#612975, @EricWF wrote:

> I wonder if we should consider this a breaking ABI change and control it using a `_LIBCPP_ABI` macro. @mclow.lists thoughts?


This is forward-compatible (as in clients built against an older libc++ would be happy with this version) but not backwards-compatible (as in clients built against this version would not be able to run against an older libc++). Has libc++ been aiming to maintain compatibility in both directions?


https://reviews.llvm.org/D27387