| // Copyright 2017 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 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use iter::FromIterator; |
| |
| /// Collapses all unit items from an iterator into one. |
| /// |
| /// This is more useful when combined with higher-level abstractions, like |
| /// collecting to a `Result<(), E>` where you only care about errors: |
| /// |
| /// ``` |
| /// use std::io::*; |
| /// let data = vec![1, 2, 3, 4, 5]; |
| /// let res: Result<()> = data.iter() |
| /// .map(|x| writeln!(stdout(), "{}", x)) |
| /// .collect(); |
| /// assert!(res.is_ok()); |
| /// ``` |
| #[stable(feature = "unit_from_iter", since = "1.23.0")] |
| impl FromIterator<()> for () { |
| fn from_iter<I: IntoIterator<Item=()>>(iter: I) -> Self { |
| iter.into_iter().for_each(|()| {}) |
| } |
| } |
