[libcxx-commits] [libcxx] [libc++] Fix flat_{multi}set insert_range (PR #137462)

[Louis Dionne via libcxx-commits]

ldionne wrote:

Per discussion just now, I do see @huixie90 's point of view where this isn't really a bug in the Standard per se, so no LWG issue is required. LGTM with comments addressed.

https://github.com/llvm/llvm-project/pull/137462