Function rfind

src/include/string_ref.h:220–227

Find the last occurrence of substring s *this, but only those occurrences earlier than position pos.

    /// Find the last occurrence of substring s *this, but only those
    /// occurrences earlier than position pos.
    size_type rfind (string_ref s, size_t pos=npos) const {
        if (pos > size())
            pos = size();
        const_reverse_iterator b = this->crbegin()+(size()-pos);
        const_reverse_iterator e = this->crend();
        const_reverse_iterator i = std::search (b, e, s.crbegin(), s.crend(), traits::eq);
        return i == e ? npos : (reverse_distance(this->crbegin(),i) - s.size() + 1);
    }

    /// Find the last occurrence of character c in *this, but only those
    /// occurrences earlier than position pos.