32 Regular expressions library [re]

32.10 Regular expression algorithms [re.alg]

32.10.1 Exceptions [re.except]

The algorithms described in subclause [re.alg] may throw an exception of type regex_­error.
If such an exception e is thrown, e.code() shall return either regex_­constants​::​error_­complexity or regex_­constants​::​error_­stack.