Method substring

visage_utils/string_utils.h:387–389

    bool isEmpty() const { return string_.empty(); }

    String substring(size_t position = 0, size_t count = std::u32string::npos) const {
      return string_.substr(position, count);
    }

    String trim() const {
      size_t start = string_.find_first_not_of(U" \t\n\r");