avoid implicit conversion of string to regExp in string-list matching
Currently have this type of code:
labelList findStrings(const std::string& re, const UList<StringType>& lst, const bool invert=false)
{
const regExp matcher(re);
return findMatchingStrings(matcher, lst, invert);
}
This means that the seeming innocuous call
findStrings(someWord, listOfString);
actually incurs an additional regExp allocation and then uses this for performing the match. If the word contains a '.' meta-character, this could well lead to false positives. In either case, we would be using the regex matcher when a simple string compare would also work.