迭代切片的值而不是Rust中的引用？ [英] Iterating over a slice's values instead of references in Rust?

问题描述

当循环遍历一片结构时，我得到的值是一个引用（很好），但在某些情况下，必须将 var 写为<在许多地方code>（* var）。

When looping over a slice of structs, the value I get is a reference (which is fine), however in some cases it's annoying to have to write var as (*var) in many places.

有没有更好的方法来避免重新声明变量？

Is there a better way to avoid re-declaring the variable?

fn my_fn(slice: &[MyStruct]) {
    for var in slice {
        let var = *var;  // <-- how to avoid this?

        // Without the line above, errors in comments occur:

        other_fn(var);  // <-- expected struct `MyStruct`, found reference

        if var != var.other {
            // ^^ trait `&MyStruct: std::cmp::PartialEq<MyStruct>>` not satisfied
            foo();
        }
    }
}

---

请参阅：实际错误输出（更加神秘）。

推荐答案

您可以在模式：

//  |
//  v
for &var in slice {
    other_fn(var);
}

然而，这仅适用于 复制 -types ！如果你有非复制，但克隆 -only类型，你可以使用 cloned（）迭代器适配器;有关更多信息，请参阅Chris Emerson的答案。如果您的类型不是克隆，则您没有机会这样做。

However, this only works for Copy-types! If you have non-Copy, but Clone-only types, you could use the cloned() iterator adapter; see Chris Emerson's answer for more information. If you have types that aren't Clone, you have no chance to do it.

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