#![allow(unused, clippy::needless_if, clippy::suspicious_map, clippy::iter_count)] use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, LinkedList}; #[warn(clippy::needless_collect)] #[allow(unused_variables, clippy::iter_cloned_collect, clippy::iter_next_slice)] fn main() { let sample = [1; 5]; let len = sample.iter().collect::<Vec<_>>().len(); if sample.iter().collect::<Vec<_>>().is_empty() { // Empty } sample.iter().cloned().collect::<Vec<_>>().contains(&1); // #7164 HashMap's and BTreeMap's `len` usage should not be linted sample.iter().map(|x| (x, x)).collect::<HashMap<_, _>>().len(); sample.iter().map(|x| (x, x)).collect::<BTreeMap<_, _>>().len(); sample.iter().map(|x| (x, x)).collect::<HashMap<_, _>>().is_empty(); sample.iter().map(|x| (x, x)).collect::<BTreeMap<_, _>>().is_empty(); // Notice the `HashSet`--this should not be linted sample.iter().collect::<HashSet<_>>().len(); // Neither should this sample.iter().collect::<BTreeSet<_>>().len(); sample.iter().collect::<LinkedList<_>>().len(); sample.iter().collect::<LinkedList<_>>().is_empty(); sample.iter().cloned().collect::<LinkedList<_>>().contains(&1); sample.iter().collect::<LinkedList<_>>().contains(&&1); // `BinaryHeap` doesn't have `contains` method sample.iter().collect::<BinaryHeap<_>>().len(); sample.iter().collect::<BinaryHeap<_>>().is_empty(); // Don't lint string from str let _ = ["", ""].into_iter().collect::<String>().is_empty(); let _ = sample.iter().collect::<HashSet<_>>().is_empty(); let _ = sample.iter().collect::<HashSet<_>>().contains(&&0); struct VecWrapper<T>(Vec<T>); impl<T> core::ops::Deref for VecWrapper<T> { type Target = Vec<T>; fn deref(&self) -> &Self::Target { &self.0 } } impl<T> IntoIterator for VecWrapper<T> { type IntoIter = <Vec<T> as IntoIterator>::IntoIter; type Item = <Vec<T> as IntoIterator>::Item; fn into_iter(self) -> Self::IntoIter { self.0.into_iter() } } impl<T> FromIterator<T> for VecWrapper<T> { fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self { Self(Vec::from_iter(iter)) } } let _ = sample.iter().collect::<VecWrapper<_>>().is_empty(); let _ = sample.iter().collect::<VecWrapper<_>>().contains(&&0); #[allow(clippy::double_parens)] { Vec::<u8>::new().extend((0..10).collect::<Vec<_>>()); foo((0..10).collect::<Vec<_>>()); bar((0..10).collect::<Vec<_>>(), (0..10).collect::<Vec<_>>()); baz((0..10), (), ('a'..='z').collect::<Vec<_>>()) } let values = [1, 2, 3, 4]; let mut out = vec![]; values.iter().cloned().map(|x| out.push(x)).collect::<Vec<_>>(); let _y = values.iter().cloned().map(|x| out.push(x)).collect::<Vec<_>>(); // this is fine } fn foo(_: impl IntoIterator<Item = usize>) {} fn bar<I: IntoIterator<Item = usize>>(_: Vec<usize>, _: I) {} fn baz<I: IntoIterator<Item = usize>>(_: I, _: (), _: impl IntoIterator<Item = char>) {}