對象指針本身也是接口中的一個參量。

然而，在更廣闊的計算機領域中，多態這個詞並不只是局限在類繼承和虛函數上。只要是同名函數能夠根據參數的類型不同而獲得不同的實現，我們都可以叫它“多態”。

多態可以分成三類，Ad hoc 多態(Ad hoc ~)，參數化多態(Parametric ~)，子類型多態(Subtype ~)。

對於Ad hoc多態，首先要神會這個詞，我個人通常將其簡單替換成 ”The fucking“，“那個多態”。C++中的重載，例子中的函數 f3() 就屬於此類。多個同名函數根據參數的不同，選擇不同的實現。第二種的典型例子，就是例子中的f1()，通過參數化類型來完成多態。第三種，局限於多態化的函數參數類型是Subtyping的關系，它是C++上狹義的多態。

參考：

Polymorphism (computer science)

https://zhuanlan.zhihu.com/p/20413538

• Ad hoc polymorphism: when a function denotes different and potentially heterogeneous implementations depending on a limited range of individually specified types and combinations. Ad hoc polymorphism is supported in many languages using function overloading.
• Parametric polymorphism: when code is written without mention of any specific type and thus can be used transparently with any number of new types. In the object-oriented programming community, this is often known as generics or generic programming. In the functional programming community, this is often shortened to polymorphism
  .
• Subtyping (also called subtype polymorphism or inclusion polymorphism): when a name denotes instances of many different classes related by some common superclass.^[3]

多態是面向接口編程的概念