Method lowercase

common/jinja/string.cpp:130–136

    });
}
string string::lowercase() {
    return apply_transform(*this, [](const std::string & s) {
        std::string res = s;
        std::transform(res.begin(), res.end(), res.begin(), ::tolower);
        return res;
    });
}
string string::capitalize() {
    return apply_transform(*this, [](const std::string & s) {
        if (s.empty()) return s;