diff --git a/src/ch17-03-oo-design-patterns.md b/src/ch17-03-oo-design-patterns.md index d26b91b..6e4f567 100644 --- a/src/ch17-03-oo-design-patterns.md +++ b/src/ch17-03-oo-design-patterns.md @@ -69,15 +69,9 @@ struct Draft {} impl State for Draft {} ``` -Listing 17-12: Definition of a `Post` struct and a `new` -function that creates a new `Post` instance, a `State` trait, and a `Draft` -struct that implements `State` - -When we create a new `Post`, we set its `state` field to a `Some` value holding -a `Box` pointing to a new instance of the `Draft` struct. This ensures whenever -we create a new instance of `Post`, it'll start out as a draft. Because the -`state` field of `Post` is private, there's no way to create a `Post` in any -other state! +列表17-12: 定义一个`Post`结构, 一个`Post`结构的创建一个新的`Post`实例的关联函数`new`, 一个`State`trait, 和一个实现了`State`的结构`Draft`. + +当我们创建一个新的`Post`实例时, 我们把它的`state`字段设为一个持有指向一个新的`Draft`结构实例的`Box`的`Some`类型的值. 这就确保无论何时我们创建一个`Post`类型的新实例时, 它总是处于草稿状态. 因为`Post`的`state`字段是私有的, 也就没有办法创建一个处于其它状态的`Post`! ### Storing the Text of the Post Content