fn from_iter(iter: T) -> Self

where

T: IntoIterator;

}Run

It is rarely necessary to implement this trait directly, as implementing theIterator trait for a type will provide a default implementation of

FromIterator (see the "Implementors" section below).

See also:IntoIterator.

Examples

Basic usage:

use std::iter::FromIterator;

let five_fives = std::iter::repeat(5).take(5);

let v = Vec::from_iter(five_fives);

assert_eq!(v, vec![5, 5, 5, 5, 5]);Run

Usingcollect to implicitly use FromIterator:

let five_fives = std::iter::repeat(5).take(5);

let v: Vec = five_fives.collect();

assert_eq!(v, vec![5, 5, 5, 5, 5]);Run

ImplementingFromIterator for your type:

use std::iter::FromIterator;

// A sample collection, that's just a wrapper over Vec

[derive(Debug)]

struct MyCollection(Vec);

// Let's give it some methods so we can create one and add things to it

impl MyCollection {

fn new() -> MyCollection {

MyCollection(Vec::new())

}

fn add(&mut self, elem: i32) {

self.0.push(elem);

}

}

// and we'll implement FromIterator

impl FromIterator for MyCollection {

fn from_iter>(iter: I) -> Self {

let mut c = MyCollection::new();

for i in iter {

c.add(i);

}

c

}

}

// Now we can make a new iterator...

let iter = (0..5).into_iter();

// ... and make a MyCollection out of it

let c = MyCollection::from_iter(iter);

assert_eq!(c.