#![warn(clippy::get_first)] #![allow(clippy::useless_vec)] use std::collections::{BTreeMap, HashMap, VecDeque}; struct Bar { arr: [u32; 3], } impl Bar { fn get(&self, pos: usize) -> Option<&u32> { self.arr.get(pos) } } fn main() { let x = vec![2, 3, 5]; let _ = x.first(); //~^ ERROR: accessing first element with `x.get(0)` let _ = x.get(1); let _ = x[0]; let y = [2, 3, 5]; let _ = y.first(); //~^ ERROR: accessing first element with `y.get(0)` let _ = y.get(1); let _ = y[0]; let z = &[2, 3, 5]; let _ = z.first(); //~^ ERROR: accessing first element with `z.get(0)` let _ = z.get(1); let _ = z[0]; let vecdeque: VecDeque<_> = x.iter().cloned().collect(); let hashmap: HashMap = HashMap::from_iter(vec![(0, 'a'), (1, 'b')]); let btreemap: BTreeMap = BTreeMap::from_iter(vec![(0, 'a'), (1, 'b')]); let _ = vecdeque.get(0); // Do not lint, because VecDeque is not slice. let _ = hashmap.get(&0); // Do not lint, because HashMap is not slice. let _ = btreemap.get(&0); // Do not lint, because BTreeMap is not slice. let bar = Bar { arr: [0, 1, 2] }; let _ = bar.get(0); // Do not lint, because Bar is struct. let non_primitives = [vec![1, 2], vec![3, 4]]; let _ = non_primitives.first(); //~^ ERROR: accessing first element with `non_primitives.get(0)` }