特徵
Rust 可讓您依據特徵對型別進行抽象化處理，這與介面相似：
Speaker Notes
This slide and its sub-slides should take about 10 minutes.
-
特徵用於定義型別必須具有哪幾個方法，才能實作該特徵。
-
In the “Generics” segment, next, we will see how to build functionality that is generic over all types implementing a trait.