Test::Regexp is intended to test regular expressions. Given a subject
 string and a regular expression (aka pattern), the module not only
 tests whether the regular expression complete matches the subject
 string, it performs a utf8::upgrade or utf8::downgrade on the subject
 string and performs the tests again, if necessary. Furthermore, given
 a pattern with capturing parenthesis, it checks whether all captures
 are present, and in the right order. Both named and unnamed captures
 are checked.