#![warn(clippy::all, clippy::pedantic)] #![allow(clippy::let_underscore_untyped)] #![allow(clippy::missing_docs_in_private_items)] #![allow(clippy::map_identity)] #![allow(clippy::redundant_closure)] #![allow(clippy::unnecessary_wraps)] #![feature(result_flattening)] fn main() { // mapping to Option on Iterator fn option_id(x: i8) -> Option<i8> { Some(x) } let option_id_ref: fn(i8) -> Option<i8> = option_id; let option_id_closure = |x| Some(x); let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id).collect(); let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id_ref).collect(); let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id_closure).collect(); let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(|x| x.checked_add(1)).collect(); // mapping to Iterator on Iterator let _: Vec<_> = vec![5_i8; 6].into_iter().flat_map(|x| 0..x).collect(); // mapping to Option on Option let _: Option<_> = (Some(Some(1))).and_then(|x| x); // mapping to Result on Result let _: Result<_, &str> = (Ok(Ok(1))).and_then(|x| x); issue8734(); issue8878(); } fn issue8734() { let _ = [0u8, 1, 2, 3] .into_iter() .flat_map(|n| match n { 1 => [n .saturating_add(1) .saturating_add(1) .saturating_add(1) .saturating_add(1) .saturating_add(1) .saturating_add(1) .saturating_add(1) .saturating_add(1)], n => [n], }); } #[allow(clippy::bind_instead_of_map)] // map + flatten will be suggested to `and_then`, but afterwards `map` is suggested again #[rustfmt::skip] // whitespace is important for this one fn issue8878() { std::collections::HashMap::<u32, u32>::new() .get(&0) .and_then(|_| { // we need some newlines // so that the span is big enough // for a split output of the diagnostic Some("") // whitespace beforehand is important as well }); }