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Drop

Drop trait 只有一个方法:drop,它会在对象离开作用域时自动调用。Drop trait 的主要用途是释放实现该 trait 的实例所拥有的资源。

BoxVecStringFileProcess 是一些实现了 Drop trait 以释放资源的类型示例。你也可以为任何自定义数据类型手动实现 Drop trait。

下面的例子在 drop 函数中添加了一个控制台打印,用于宣告它被调用的时机。

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下面是一个更实用的例子,展示如何使用 Drop 特质在不再需要临时文件时自动清理它们:

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