Iterator::any - Rust By Example
Description: A description

# Iterator::any

`Iterator::any` is a function which when passed an iterator, will return `true` if any element satisfies the predicate. Otherwise `false`. Its signature:

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

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

    fn main() {
        let vec1 = vec![1, 2, 3];
        let vec2 = vec![4, 5, 6];

        // `iter()` for vecs yields `&i32`. Destructure to `i32`.
        println!("2 in vec1: {}", vec1.iter()     .any(|&x| x == 2));
        // `into_iter()` for vecs yields `i32`. No destructuring required.
        println!("2 in vec2: {}", vec2.into_iter().any(| x| x == 2));

        let array1 = [1, 2, 3];
        let array2 = [4, 5, 6];

        // `iter()` for arrays yields `&i32`.
        println!("2 in array1: {}", array1.iter()     .any(|&x| x == 2));
        // `into_iter()` for arrays unusually yields `&i32`.
        println!("2 in array2: {}", array2.into_iter().any(|&x| x == 2));
    }

### See also:

`std::iter::Iterator::any`