C ++成员函数的使用无效，你忘记了（）吗？

I'm working on an assignment where I create my own container using templates. The container I am required to use is called Smaph, which takes in two pairs of numbers and does a variety of functions with them. I am only allowed to make a header file for this assignment. I've created a singly-linked class slink, that takes one template argument.I'm working on an assignment where I create my