OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=66851
Crash type: UNKNOWN READ
Crash state:
boost::re_detail_500::basic_regex_formatter<std::__1::ostream_iterator<char, cha
boost::re_detail_500::basic_regex_formatter<std::__1::ostream_iterator<char, cha
std::__1::ostream_iterator<char, char, std::__1::char_traits<char> > boost::re_d