[Rust] std::iter::IntoIterator

---

use std::iter::{IntoIterator};
 
struct Foo(Vec<i32>);
 
impl Foo {
    fn new() -> Foo {
        Foo(Vec::new())
    }
    
    fn add(&mut self, item: i32) {
        self.0.push(item);
    }
}
 
impl IntoIterator for Foo {
    type Item = i32;
    type IntoIter = ::std::vec::IntoIter<i32>;
    
    fn into_iter(self) -> Self::IntoIter {
        self.0.into_iter()
    }
}
 
fn main()
{
    let mut foo = Foo::new();
    
    foo.add(1);
    foo.add(2);
    foo.add(3);
    
    for item in foo {
        println!("{} ", item);
    }
}

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이렇게 됩니다.

---

impl<'a> IntoIterator for &'a Foo {
    type Item = &'a i32;
    type IntoIter = ::std::slice::Iter<'a, i32>;
    
    fn into_iter(self) -> Self::IntoIter {
        (&self.0).into_iter()
    }
}

---

요것도 추가하면

for item in &foo {
    println!("{} ", item);
}

이렇게도 쓸 수 있습니다.