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

当循环一个结构片段时，我得到的值是一个引用(这很好)，但是在某些情况下，必须将 var 写为 (*var) 很烦人在很多地方.

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();
        }
    }
}

<小时>

参见:实际错误输出(更神秘).

推荐答案

你可以在 模式:

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

然而，这只适用于Copy-types！如果你有一个没有实现 Copy 但实现了 Clone 的类型，你可以使用 cloned() 迭代器适配器；有关详细信息，请参阅 Chris Emerson 的回答.

However, this only works for Copy-types! If you have a type that doesn't implement Copy but does implement Clone, you could use the cloned() iterator adapter; see Chris Emerson's answer for more information.

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