// Copyright 2018 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. #![feature(nll)] struct List { value: T, next: Option>>, } fn to_refs(mut list: &mut List) -> Vec<&mut T> { let mut result = vec![]; loop { result.push(&mut list.value); if let Some(n) = list.next.as_mut() { list = n; } else { return result; } } } fn main() { let mut list = List { value: 1, next: None }; let vec = to_refs(&mut list); assert_eq!(vec![&mut 1], vec); }