Perfect forwarding

• Perfect forwarding

• https://tjsw.medium.com/%E6%BD%AE-c-11-perfect-forwarding-%E5%AE%8C%E7%BE%8E%E8%BD%89%E7%99%BC%E4%BD%A0%E7%9A%84%E9%9C%80%E6%B1%82-%E6%B7%B1%E5%BA%A6%E8%A7%A3%E6%9E%90-f991830bcd84