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@ -59,7 +59,7 @@ Rust 需要明确地知道一个特定类型的值占据了多少内存空间,
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```rust
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fn foobar_1(thing: &dyn MyThing) {} // OK
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fn foobar_2(thing: Box<dyn MyThing>) {} // OK
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fn foobar_3(thing: MyThing) {} // ERROR!
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fn foobar_3(thing: dyn MyThing) {} // ERROR!
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```
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如上所示,只能通过引用或 `Box` 的方式来使用特征对象,直接使用将报错!
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