Indeed, swap in your printout there is just defined as now taking *a and *b and then it also uses the * later, but we'll come back to what the different uses of the * means, but for now I claim conceptually it just means swap has access to the locations of its parameters.

的确，在打印资料中的swap被定义为,携带*a和*b，之后它也是带*号的，但是我们将说明*的不同用法，现在，我断言swap可以,使用参数的地址。

哈佛公开课 - 计算机科学课程节选