timshen added a comment. I'm not fully equipped with the context right now, but something doesn't add up. if `__neg_chars_.empty()` check is removed, the `(__neg_mask_ == 0)` above should be removed too. They have to be consistent.
However, there is more weirdness in it. The comment above describes the intention: union(complement(union(__neg_chars_, __neg_mask_)), other cases...) With the `__neg_chars_.empty()` and `(__neg_mask_ == 0)` removed, I believe that the code exactly matches the comment. Let's see what happens when users don't specify any negative class or chars. __neg_chars_ and __neg_mask_ will be empty sets, and `union(complement(union(__neg_chars_, __neg_mask_)), other cases...)` always evaluate to true, which means it always matches all characters. This can't be right. It's likely that the comment description doesn't fully describe the intended behavior. I think we need to figure that out first. Repository: rCXX libc++ https://reviews.llvm.org/D50534 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
