Method rfind

uspace/lib/cpp/include/__bits/string/string.hpp:1246–1249

            }

            size_type rfind(const basic_string& str, size_type pos = npos) const noexcept
            {
                return rfind(str.c_str(), pos, str.size());
            }

            size_type rfind(const value_type* str, size_type pos, size_type len) const noexcept
            {