#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#![feature(new_range_api)]
use core::range::RangeFrom;
fn main() {
    let mut i = RangeFrom::from(3..).iter().map(|n| n * n);
    assert_eq!(i.next(), Some(9));
    assert_eq!(i.next(), Some(16));
    assert_eq!(i.next(), Some(25));
}