通过迭代器搜索

Iterator::find 是一个函数，它遍历一个迭代器，并搜索第一个满足某个条件的值。如果没有值满足该条件，则返回 None。它的签名如下：

pub trait Iterator {
    // The type being iterated over.
    type Item;

    // `find` takes `&mut self` meaning the caller may be borrowed
    // and modified, but not consumed.
    fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where
        // `FnMut` meaning any captured variable may at most be
        // modified, not consumed. `&Self::Item` states it takes
        // arguments to the closure by reference.
        P: FnMut(&Self::Item) -> bool;
}

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Iterator::find 返回对项的引用。但如果你想要该项的索引，请使用 Iterator::position。

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另请参阅

std::iter::Iterator::find

std::iter::Iterator::find_map

std::iter::Iterator::position

std::iter::Iterator::rposition