// will emits unused mut warnings after fixing #![allow(unused_mut)] // will emits needless collect warnings after fixing #![allow(clippy::needless_collect, clippy::drain_collect)] #![warn(clippy::iter_with_drain)] use std::collections::{BinaryHeap, HashMap, HashSet, VecDeque}; fn full() { let mut a = vec!["aaa".to_string(), "bbb".to_string()]; let mut a: BinaryHeap<_> = a.drain(..).collect(); let mut a: HashSet<_> = a.drain().collect(); let mut a: VecDeque<_> = a.drain().collect(); let mut a: Vec<_> = a.drain(..).collect(); let mut a: HashMap<_, _> = a.drain(..).map(|x| (x.clone(), x)).collect(); let _: Vec<(String, String)> = a.drain().collect(); } fn closed() { let mut a = vec!["aaa".to_string(), "bbb".to_string()]; let mut a: BinaryHeap<_> = a.drain(0..).collect(); let mut a: HashSet<_> = a.drain().collect(); let mut a: VecDeque<_> = a.drain().collect(); let mut a: Vec<_> = a.drain(..a.len()).collect(); let mut a: HashMap<_, _> = a.drain(0..a.len()).map(|x| (x.clone(), x)).collect(); let _: Vec<(String, String)> = a.drain().collect(); } fn should_not_help() { let mut a = vec!["aaa".to_string(), "bbb".to_string()]; let mut a: BinaryHeap<_> = a.drain(1..).collect(); let mut a: HashSet<_> = a.drain().collect(); let mut a: VecDeque<_> = a.drain().collect(); let mut a: Vec<_> = a.drain(..a.len() - 1).collect(); let mut a: HashMap<_, _> = a.drain(1..a.len() - 1).map(|x| (x.clone(), x)).collect(); let _: Vec<(String, String)> = a.drain().collect(); let mut b = vec!["aaa".to_string(), "bbb".to_string()]; let _: Vec<_> = b.drain(0..a.len()).collect(); } fn _closed_range(mut x: Vec) { let _: Vec = x.drain(0..=x.len()).collect(); } fn _with_mut(x: &mut Vec, y: &mut VecDeque) { let _: Vec = x.drain(..).collect(); let _: Vec = y.drain(..).collect(); } #[derive(Default)] struct Bomb { fire: Vec, } fn should_not_help_0(bomb: &mut Bomb) { let _: Vec = bomb.fire.drain(..).collect(); } fn main() { full(); closed(); should_not_help(); should_not_help_0(&mut Bomb::default()); }