1 #![feature(plugin, inclusive_range_syntax, custom_attribute)]
4 use std::collections::*;
7 static STATIC: [usize; 4] = [0, 1, 8, 16];
8 const CONST: [usize; 4] = [0, 1, 8, 16];
11 fn for_loop_over_option_and_result() {
13 let result = option.ok_or("x not found");
14 let v = vec![0, 1, 2];
16 // check FOR_LOOP_OVER_OPTION lint
17 #[clippy(author)]for x in option {
21 // check FOR_LOOP_OVER_RESULT lint
26 for x in option.ok_or("x not found") {
30 // make sure LOOP_OVER_NEXT lint takes precedence when next() is the last call
32 for x in v.iter().next() {
36 // make sure we lint when next() is not the last call in the chain
37 for x in v.iter().next().and(Some(0)) {
41 for x in v.iter().next().ok_or("x not found") {
45 // check for false positives
47 // for loop false positive
52 // while let false positive for Option
53 while let Some(x) = option {
58 // while let false positive for Result
59 while let Ok(x) = result {
65 struct Unrelated(Vec<u8>);
67 fn next(&self) -> std::slice::Iter<u8> {
71 fn iter(&self) -> std::slice::Iter<u8> {
76 #[warn(needless_range_loop, explicit_iter_loop, explicit_into_iter_loop, iter_next_loop, reverse_range_loop,
77 explicit_counter_loop, for_kv_map)]
78 #[warn(unused_collect)]
79 #[allow(linkedlist, shadow_unrelated, unnecessary_mut_passed, cyclomatic_complexity, similar_names)]
80 #[allow(many_single_char_names, unused_variables)]
82 const MAX_LEN: usize = 42;
84 let mut vec = vec![1, 2, 3, 4];
85 let vec2 = vec![1, 2, 3, 4];
86 for i in 0..vec.len() {
87 println!("{}", vec[i]);
90 for i in 0..vec.len() {
91 let i = 42; // make a different `i`
92 println!("{}", vec[i]); // ok, not the `i` of the for-loop
95 for i in 0..vec.len() {
101 println!("{:?}", STATIC[j]);
105 println!("{:?}", CONST[j]);
108 for i in 0..vec.len() {
109 println!("{} {}", vec[i], i);
111 for i in 0..vec.len() {
112 // not an error, indexing more than one variable
113 println!("{} {}", vec[i], vec2[i]);
116 for i in 0..vec.len() {
117 println!("{}", vec2[i]);
120 for i in 5..vec.len() {
121 println!("{}", vec[i]);
124 for i in 0..MAX_LEN {
125 println!("{}", vec[i]);
128 for i in 0..=MAX_LEN {
129 println!("{}", vec[i]);
133 println!("{}", vec[i]);
137 println!("{}", vec[i]);
140 for i in 5..vec.len() {
141 println!("{} {}", vec[i], i);
145 println!("{} {}", vec[i], i);
156 for i in MAX_LEN..0 {
165 // not an error, this is the range with only one element “5”
170 // not an error, the start index is less than the end index
179 for i in (10..0).map(|x| x * 2) {
180 // not an error, it can't be known what arbitrary methods do to a range
184 // testing that the empty range lint folds constants
189 for i in (5 + 2)..(3 - 1) {
193 for i in (5 + 2)..(8 - 1) {
197 for i in (2 * 2)..(2 * 3) {
198 // no error, 4..6 is fine
204 // no error, not constant-foldable
210 // no error, id_col does not exist outside the loop
211 let mut id_col = vec![0f64; 10];
215 for _v in vec.iter() {}
217 for _v in vec.iter_mut() {}
219 let out_vec = vec![1, 2, 3];
220 for _v in out_vec.into_iter() {}
222 let array = [1, 2, 3];
223 for _v in array.into_iter() {}
225 for _v in &vec {} // these are fine
226 for _v in &mut vec {} // these are fine
228 for _v in [1, 2, 3].iter() {}
230 for _v in (&mut [1, 2, 3]).iter() {} // no error
232 for _v in [0; 32].iter() {}
234 for _v in [0; 33].iter() {} // no error
236 let ll: LinkedList<()> = LinkedList::new();
237 for _v in ll.iter() {}
239 let vd: VecDeque<()> = VecDeque::new();
240 for _v in vd.iter() {}
242 let bh: BinaryHeap<()> = BinaryHeap::new();
243 for _v in bh.iter() {}
245 let hm: HashMap<(), ()> = HashMap::new();
246 for _v in hm.iter() {}
248 let bt: BTreeMap<(), ()> = BTreeMap::new();
249 for _v in bt.iter() {}
251 let hs: HashSet<()> = HashSet::new();
252 for _v in hs.iter() {}
254 let bs: BTreeSet<()> = BTreeSet::new();
255 for _v in bs.iter() {}
257 for _v in vec.iter().next() {}
259 let u = Unrelated(vec![]);
260 for _v in u.next() {} // no error
261 for _v in u.iter() {} // no error
263 let mut out = vec![];
264 vec.iter().cloned().map(|x| out.push(x)).collect::<Vec<_>>();
265 let _y = vec.iter().cloned().map(|x| out.push(x)).collect::<Vec<_>>(); // this is fine
267 // Loop with explicit counter variable
279 // Potential false positives
370 let mut _x = &mut index;
380 println!("index: {}", index);
382 for_loop_over_option_and_result();
384 let m: HashMap<u64, u64> = HashMap::new();
389 let m: Rc<HashMap<u64, u64>> = Rc::new(HashMap::new());
392 // Here the `*` is not actually necesarry, but the test tests that we don't
394 // `in *m.values()` as we used to
397 let mut m: HashMap<u64, u64> = HashMap::new();
398 for (_, v) in &mut m {
402 let m: &mut HashMap<u64, u64> = &mut HashMap::new();
403 for (_, v) in &mut *m {
407 let m: HashMap<u64, u64> = HashMap::new();
409 for (k, _value) in rm {
415 fn f<T>(_: &T, _: &T) -> bool {
418 fn g<T>(_: &mut [T], _: usize, _: usize) {
421 for i in 1..vec.len() {
422 if f(&vec[i - 1], &vec[i]) {
423 g(&mut vec, i - 1, i);
427 for mid in 1..vec.len() {
428 let (_, _) = vec.split_at(mid);
432 #[allow(used_underscore_binding)]
433 fn test_for_kv_map() {
434 let m: HashMap<u64, u64> = HashMap::new();
436 // No error, _value is actually used
437 for (k, _value) in &m {
444 fn partition<T: PartialOrd + Send>(v: &mut [T]) -> usize {
445 let pivot = v.len() - 1;
448 if v[j] <= v[pivot] {
457 const LOOP_OFFSET: usize = 5000;
459 #[warn(needless_range_loop)]
460 pub fn manual_copy(src: &[i32], dst: &mut [i32], dst2: &mut [i32]) {
461 // plain manual memcpy
462 for i in 0..src.len() {
467 for i in 0..src.len() {
468 dst[i + 10] = src[i];
472 for i in 0..src.len() {
473 dst[i] = src[i + 10];
477 for i in 11..src.len() {
478 dst[i] = src[i - 10];
481 // overwrite entire dst
482 for i in 0..dst.len() {
486 // manual copy with branch - can't easily convert to memcpy!
487 for i in 0..src.len() {
494 // multiple copies - suggest two memcpy statements
497 dst2[i + 500] = src[i]
500 // this is a reversal - the copy lint shouldn't be triggered
501 for i in 10..LOOP_OFFSET {
502 dst[i + LOOP_OFFSET] = src[LOOP_OFFSET - i];
506 // Offset in variable
507 for i in 10..LOOP_OFFSET {
508 dst[i + LOOP_OFFSET] = src[i - some_var];
511 // Non continuous copy - don't trigger lint
516 let src_vec = vec![1, 2, 3, 4, 5];
517 let mut dst_vec = vec![0, 0, 0, 0, 0];
519 // make sure vectors are supported
520 for i in 0..src_vec.len() {
521 dst_vec[i] = src_vec[i];
524 // lint should not trigger when either
525 // source or destination type is not
526 // slice-like, like DummyStruct
527 struct DummyStruct(i32);
529 impl ::std::ops::Index<usize> for DummyStruct {
532 fn index(&self, _: usize) -> &i32 {
537 let src = DummyStruct(5);
538 let mut dst_vec = vec![0; 10];
545 #[warn(needless_range_loop)]
546 pub fn manual_clone(src: &[String], dst: &mut [String]) {
547 for i in 0..src.len() {
548 dst[i] = src[i].clone();
552 #[warn(needless_range_loop)]
553 pub fn manual_copy_same_destination(dst: &mut [i32], d: usize, s: usize) {
554 // Same source and destination - don't trigger lint
555 for i in 0..dst.len() {
556 dst[d + i] = dst[s + i];
562 fn new_for_index(index: usize) -> Self;
563 fn index(&self) -> usize;
566 pub fn test<H: Handle>() -> H {
568 let next_handle = H::new_for_index(x);
569 println!("{}", next_handle.index());