#![feature(plugin, step_by, inclusive_range_syntax)] #![plugin(clippy)] use std::collections::*; use std::rc::Rc; static STATIC: [usize; 4] = [ 0, 1, 8, 16 ]; const CONST: [usize; 4] = [ 0, 1, 8, 16 ]; #[deny(clippy)] fn for_loop_over_option_and_result() { let option = Some(1); let result = option.ok_or("x not found"); let v = vec![0,1,2]; // check FOR_LOOP_OVER_OPTION lint for x in option { println!("{}", x); } // check FOR_LOOP_OVER_RESULT lint for x in result { println!("{}", x); } for x in option.ok_or("x not found") { println!("{}", x); } // make sure LOOP_OVER_NEXT lint takes precedence when next() is the last call in the chain for x in v.iter().next() { println!("{}", x); } // make sure we lint when next() is not the last call in the chain for x in v.iter().next().and(Some(0)) { println!("{}", x); } for x in v.iter().next().ok_or("x not found") { println!("{}", x); } // check for false positives // for loop false positive for x in v { println!("{}", x); } // while let false positive for Option while let Some(x) = option { println!("{}", x); break; } // while let false positive for Result while let Ok(x) = result { println!("{}", x); break; } } struct Unrelated(Vec); impl Unrelated { fn next(&self) -> std::slice::Iter { self.0.iter() } fn iter(&self) -> std::slice::Iter { self.0.iter() } } #[deny(needless_range_loop, explicit_iter_loop, explicit_into_iter_loop, iter_next_loop, reverse_range_loop, explicit_counter_loop, for_kv_map)] #[deny(unused_collect)] #[allow(linkedlist, shadow_unrelated, unnecessary_mut_passed, cyclomatic_complexity, similar_names)] #[allow(many_single_char_names)] fn main() { const MAX_LEN: usize = 42; let mut vec = vec![1, 2, 3, 4]; let vec2 = vec![1, 2, 3, 4]; for i in 0..vec.len() { println!("{}", vec[i]); } for i in 0..vec.len() { let i = 42; // make a different `i` println!("{}", vec[i]); // ok, not the `i` of the for-loop } for i in 0..vec.len() { let _ = vec[i]; } // ICE #746 for j in 0..4 { println!("{:?}", STATIC[j]); } for j in 0..4 { println!("{:?}", CONST[j]); } for i in 0..vec.len() { println!("{} {}", vec[i], i); } for i in 0..vec.len() { // not an error, indexing more than one variable println!("{} {}", vec[i], vec2[i]); } for i in 0..vec.len() { println!("{}", vec2[i]); } for i in 5..vec.len() { println!("{}", vec[i]); } for i in 0..MAX_LEN { println!("{}", vec[i]); } for i in 0...MAX_LEN { println!("{}", vec[i]); } for i in 5..10 { println!("{}", vec[i]); } for i in 5...10 { println!("{}", vec[i]); } for i in 5..vec.len() { println!("{} {}", vec[i], i); } for i in 5..10 { println!("{} {}", vec[i], i); } for i in 10..0 { println!("{}", i); } for i in 10...0 { println!("{}", i); } for i in MAX_LEN..0 { println!("{}", i); } for i in 5..5 { println!("{}", i); } for i in 5...5 { // not an error, this is the range with only one element “5” println!("{}", i); } for i in 0..10 { // not an error, the start index is less than the end index println!("{}", i); } for i in -10..0 { // not an error println!("{}", i); } for i in (10..0).map(|x| x * 2) { // not an error, it can't be known what arbitrary methods do to a range println!("{}", i); } // testing that the empty range lint folds constants for i in 10..5+4 { println!("{}", i); } for i in (5+2)..(3-1) { println!("{}", i); } for i in (5+2)..(8-1) { println!("{}", i); } for i in (2*2)..(2*3) { // no error, 4..6 is fine println!("{}", i); } for i in (10..8).step_by(-1) { println!("{}", i); } let x = 42; for i in x..10 { // no error, not constant-foldable println!("{}", i); } // See #601 for i in 0..10 { // no error, id_col does not exist outside the loop let mut id_col = vec![0f64; 10]; id_col[i] = 1f64; } for _v in vec.iter() { } for _v in vec.iter_mut() { } let out_vec = vec![1,2,3]; for _v in out_vec.into_iter() { } let array = [1, 2, 3]; for _v in array.into_iter() {} //~ERROR it is more idiomatic to loop over `&array` for _v in &vec { } // these are fine for _v in &mut vec { } // these are fine for _v in [1, 2, 3].iter() { } for _v in (&mut [1, 2, 3]).iter() { } // no error for _v in [0; 32].iter() {} for _v in [0; 33].iter() {} // no error let ll: LinkedList<()> = LinkedList::new(); for _v in ll.iter() { } let vd: VecDeque<()> = VecDeque::new(); for _v in vd.iter() { } let bh: BinaryHeap<()> = BinaryHeap::new(); for _v in bh.iter() { } let hm: HashMap<(), ()> = HashMap::new(); for _v in hm.iter() { } let bt: BTreeMap<(), ()> = BTreeMap::new(); for _v in bt.iter() { } let hs: HashSet<()> = HashSet::new(); for _v in hs.iter() { } let bs: BTreeSet<()> = BTreeSet::new(); for _v in bs.iter() { } for _v in vec.iter().next() { } let u = Unrelated(vec![]); for _v in u.next() { } // no error for _v in u.iter() { } // no error let mut out = vec![]; vec.iter().map(|x| out.push(x)).collect::>(); let _y = vec.iter().map(|x| out.push(x)).collect::>(); // this is fine // Loop with explicit counter variable let mut _index = 0; for _v in &vec { _index += 1 } let mut _index = 1; _index = 0; for _v in &vec { _index += 1 } // Potential false positives let mut _index = 0; _index = 1; for _v in &vec { _index += 1 } let mut _index = 0; _index += 1; for _v in &vec { _index += 1 } let mut _index = 0; if true { _index = 1 } for _v in &vec { _index += 1 } let mut _index = 0; let mut _index = 1; for _v in &vec { _index += 1 } let mut _index = 0; for _v in &vec { _index += 1; _index += 1 } let mut _index = 0; for _v in &vec { _index *= 2; _index += 1 } let mut _index = 0; for _v in &vec { _index = 1; _index += 1 } let mut _index = 0; for _v in &vec { let mut _index = 0; _index += 1 } let mut _index = 0; for _v in &vec { _index += 1; _index = 0; } let mut _index = 0; for _v in &vec { for _x in 0..1 { _index += 1; }; _index += 1 } let mut _index = 0; for x in &vec { if *x == 1 { _index += 1 } } let mut _index = 0; if true { _index = 1 }; for _v in &vec { _index += 1 } let mut _index = 1; if false { _index = 0 }; for _v in &vec { _index += 1 } let mut index = 0; { let mut _x = &mut index; } for _v in &vec { _index += 1 } let mut index = 0; for _v in &vec { index += 1 } println!("index: {}", index); for_loop_over_option_and_result(); let m : HashMap = HashMap::new(); for (_, v) in &m { let _v = v; } let m : Rc> = Rc::new(HashMap::new()); for (_, v) in &*m { let _v = v; // Here the `*` is not actually necesarry, but the test tests that we don't suggest // `in *m.values()` as we used to } let mut m : HashMap = HashMap::new(); for (_, v) in &mut m { let _v = v; } let m: &mut HashMap = &mut HashMap::new(); for (_, v) in &mut *m { let _v = v; } let m : HashMap = HashMap::new(); let rm = &m; for (k, _value) in rm { let _k = k; } test_for_kv_map(); } #[allow(used_underscore_binding)] fn test_for_kv_map() { let m : HashMap = HashMap::new(); // No error, _value is actually used for (k, _value) in &m { let _ = _value; let _k = k; } }