Function isReservedTag

unittests/catch.hpp:9849–9851

            return TestCaseInfo::None;
    }
    bool isReservedTag( std::string const& tag ) {
        return parseSpecialTag( tag ) == TestCaseInfo::None && tag.size() > 0 && !std::isalnum( tag[0] );
    }
    void enforceNotReservedTag( std::string const& tag, SourceLineInfo const& _lineInfo ) {
        CATCH_ENFORCE( !isReservedTag(tag),
                      "Tag name: [" << tag << "] is not allowed.\n"