rust/tests/ui/for_loop.stderr

error: for loop over `option`, which is an `Option`. This is more readably written as an `if let` statement.
  --> $DIR/for_loop.rs:17:14
   |
17 |     for x in option {
   |              ^^^^^^
   |
   = note: `-D for-loop-over-option` implied by `-D warnings`
   = help: consider replacing `for x in option` with `if let Some(x) = option`

error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement.
  --> $DIR/for_loop.rs:22:14
   |
22 |     for x in result {
   |              ^^^^^^
   |
   = note: `-D for-loop-over-result` implied by `-D warnings`
   = help: consider replacing `for x in result` with `if let Ok(x) = result`

error: for loop over `option.ok_or("x not found")`, which is a `Result`. This is more readably written as an `if let` statement.
  --> $DIR/for_loop.rs:26:14
   |
26 |     for x in option.ok_or("x not found") {
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider replacing `for x in option.ok_or("x not found")` with `if let Ok(x) = option.ok_or("x not found")`

error: you are iterating over `Iterator::next()` which is an Option; this will compile but is probably not what you want
  --> $DIR/for_loop.rs:32:5
   |
32 | /     for x in v.iter().next() {
33 | |         println!("{}", x);
34 | |     }
   | |_____^
   |
   = note: `-D iter-next-loop` implied by `-D warnings`

error: for loop over `v.iter().next().and(Some(0))`, which is an `Option`. This is more readably written as an `if let` statement.
  --> $DIR/for_loop.rs:37:14
   |
37 |     for x in v.iter().next().and(Some(0)) {
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider replacing `for x in v.iter().next().and(Some(0))` with `if let Some(x) = v.iter().next().and(Some(0))`

error: for loop over `v.iter().next().ok_or("x not found")`, which is a `Result`. This is more readably written as an `if let` statement.
  --> $DIR/for_loop.rs:41:14
   |
41 |     for x in v.iter().next().ok_or("x not found") {
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider replacing `for x in v.iter().next().ok_or("x not found")` with `if let Ok(x) = v.iter().next().ok_or("x not found")`

error: this loop never actually loops
  --> $DIR/for_loop.rs:53:5
   |
53 | /     while let Some(x) = option {
54 | |         println!("{}", x);
55 | |         break;
56 | |     }
   | |_____^
   |
   = note: `-D never-loop` implied by `-D warnings`

error: this loop never actually loops
  --> $DIR/for_loop.rs:59:5
   |
59 | /     while let Ok(x) = result {
60 | |         println!("{}", x);
61 | |         break;
62 | |     }
   | |_____^

error: the loop variable `i` is only used to index `vec`.
  --> $DIR/for_loop.rs:86:5
   |
86 | /     for i in 0..vec.len() {
87 | |         println!("{}", vec[i]);
88 | |     }
   | |_____^
   |
   = note: `-D needless-range-loop` implied by `-D warnings`
help: consider using an iterator
   |
86 |     for <item> in &vec {
   |         ^^^^^^

error: the loop variable `i` is only used to index `vec`.
  --> $DIR/for_loop.rs:95:5
   |
95 | /     for i in 0..vec.len() {
96 | |         let _ = vec[i];
97 | |     }
   | |_____^
   |
help: consider using an iterator
   |
95 |     for <item> in &vec {
   |         ^^^^^^

error: the loop variable `j` is only used to index `STATIC`.
   --> $DIR/for_loop.rs:100:5
    |
100 | /     for j in 0..4 {
101 | |         println!("{:?}", STATIC[j]);
102 | |     }
    | |_____^
    |
help: consider using an iterator
    |
100 |     for <item> in STATIC.iter().take(4) {
    |         ^^^^^^

error: the loop variable `j` is only used to index `CONST`.
   --> $DIR/for_loop.rs:104:5
    |
104 | /     for j in 0..4 {
105 | |         println!("{:?}", CONST[j]);
106 | |     }
    | |_____^
    |
help: consider using an iterator
    |
104 |     for <item> in CONST.iter().take(4) {
    |         ^^^^^^

error: the loop variable `i` is used to index `vec`
   --> $DIR/for_loop.rs:108:5
    |
108 | /     for i in 0..vec.len() {
109 | |         println!("{} {}", vec[i], i);
110 | |     }
    | |_____^
    |
help: consider using an iterator
    |
108 |     for (i, <item>) in vec.iter().enumerate() {
    |         ^^^^^^^^^^^

error: the loop variable `i` is only used to index `vec2`.
   --> $DIR/for_loop.rs:116:5
    |
116 | /     for i in 0..vec.len() {
117 | |         println!("{}", vec2[i]);
118 | |     }
    | |_____^
    |
help: consider using an iterator
    |
116 |     for <item> in vec2.iter().take(vec.len()) {
    |         ^^^^^^

error: the loop variable `i` is only used to index `vec`.
   --> $DIR/for_loop.rs:120:5
    |
120 | /     for i in 5..vec.len() {
121 | |         println!("{}", vec[i]);
122 | |     }
    | |_____^
    |
help: consider using an iterator
    |
120 |     for <item> in vec.iter().skip(5) {
    |         ^^^^^^

error: the loop variable `i` is only used to index `vec`.
   --> $DIR/for_loop.rs:124:5
    |
124 | /     for i in 0..MAX_LEN {
125 | |         println!("{}", vec[i]);
126 | |     }
    | |_____^
    |
help: consider using an iterator
    |
124 |     for <item> in vec.iter().take(MAX_LEN) {
    |         ^^^^^^

error: the loop variable `i` is only used to index `vec`.
   --> $DIR/for_loop.rs:128:5
    |
128 | /     for i in 0..=MAX_LEN {
129 | |         println!("{}", vec[i]);
130 | |     }
    | |_____^
    |
help: consider using an iterator
    |
128 |     for <item> in vec.iter().take(MAX_LEN + 1) {
    |         ^^^^^^

error: the loop variable `i` is only used to index `vec`.
   --> $DIR/for_loop.rs:132:5
    |
132 | /     for i in 5..10 {
133 | |         println!("{}", vec[i]);
134 | |     }
    | |_____^
    |
help: consider using an iterator
    |
132 |     for <item> in vec.iter().take(10).skip(5) {
    |         ^^^^^^

error: the loop variable `i` is only used to index `vec`.
   --> $DIR/for_loop.rs:136:5
    |
136 | /     for i in 5..=10 {
137 | |         println!("{}", vec[i]);
138 | |     }
    | |_____^
    |
help: consider using an iterator
    |
136 |     for <item> in vec.iter().take(10 + 1).skip(5) {
    |         ^^^^^^

error: the loop variable `i` is used to index `vec`
   --> $DIR/for_loop.rs:140:5
    |
140 | /     for i in 5..vec.len() {
141 | |         println!("{} {}", vec[i], i);
142 | |     }
    | |_____^
    |
help: consider using an iterator
    |
140 |     for (i, <item>) in vec.iter().enumerate().skip(5) {
    |         ^^^^^^^^^^^

error: the loop variable `i` is used to index `vec`
   --> $DIR/for_loop.rs:144:5
    |
144 | /     for i in 5..10 {
145 | |         println!("{} {}", vec[i], i);
146 | |     }
    | |_____^
    |
help: consider using an iterator
    |
144 |     for (i, <item>) in vec.iter().enumerate().take(10).skip(5) {
    |         ^^^^^^^^^^^

error: this range is empty so this for loop will never run
   --> $DIR/for_loop.rs:148:5
    |
148 | /     for i in 10..0 {
149 | |         println!("{}", i);
150 | |     }
    | |_____^
    |
    = note: `-D reverse-range-loop` implied by `-D warnings`
help: consider using the following if you are attempting to iterate over this range in reverse
    |
148 |     for i in (0..10).rev() {
    |              ^^^^^^^^^^^^^

error: this range is empty so this for loop will never run
   --> $DIR/for_loop.rs:152:5
    |
152 | /     for i in 10..=0 {
153 | |         println!("{}", i);
154 | |     }
    | |_____^
    |
help: consider using the following if you are attempting to iterate over this range in reverse
    |
152 |     for i in (0...10).rev() {
    |              ^^^^^^^^^^^^^^

error: this range is empty so this for loop will never run
   --> $DIR/for_loop.rs:156:5
    |
156 | /     for i in MAX_LEN..0 {
157 | |         println!("{}", i);
158 | |     }
    | |_____^
    |
help: consider using the following if you are attempting to iterate over this range in reverse
    |
156 |     for i in (0..MAX_LEN).rev() {
    |              ^^^^^^^^^^^^^^^^^^

error: this range is empty so this for loop will never run
   --> $DIR/for_loop.rs:160:5
    |
160 | /     for i in 5..5 {
161 | |         println!("{}", i);
162 | |     }
    | |_____^

error: this range is empty so this for loop will never run
   --> $DIR/for_loop.rs:185:5
    |
185 | /     for i in 10..5 + 4 {
186 | |         println!("{}", i);
187 | |     }
    | |_____^
    |
help: consider using the following if you are attempting to iterate over this range in reverse
    |
185 |     for i in (5 + 4..10).rev() {
    |              ^^^^^^^^^^^^^^^^^

error: this range is empty so this for loop will never run
   --> $DIR/for_loop.rs:189:5
    |
189 | /     for i in (5 + 2)..(3 - 1) {
190 | |         println!("{}", i);
191 | |     }
    | |_____^
    |
help: consider using the following if you are attempting to iterate over this range in reverse
    |
189 |     for i in ((3 - 1)..(5 + 2)).rev() {
    |              ^^^^^^^^^^^^^^^^^^^^^^^^

error: this range is empty so this for loop will never run
   --> $DIR/for_loop.rs:193:5
    |
193 | /     for i in (5 + 2)..(8 - 1) {
194 | |         println!("{}", i);
195 | |     }
    | |_____^

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:215:15
    |
215 |     for _v in vec.iter() {}
    |               ^^^^^^^^^^ help: to write this more concisely, try: `&vec`
    |
    = note: `-D explicit-iter-loop` implied by `-D warnings`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:217:15
    |
217 |     for _v in vec.iter_mut() {}
    |               ^^^^^^^^^^^^^^ help: to write this more concisely, try: `&mut vec`

error: it is more idiomatic to loop over containers instead of using explicit iteration methods`
   --> $DIR/for_loop.rs:220:15
    |
220 |     for _v in out_vec.into_iter() {}
    |               ^^^^^^^^^^^^^^^^^^^ help: to write this more concisely, try: `out_vec`
    |
    = note: `-D explicit-into-iter-loop` implied by `-D warnings`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:223:15
    |
223 |     for _v in array.into_iter() {}
    |               ^^^^^^^^^^^^^^^^^ help: to write this more concisely, try: `&array`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:228:15
    |
228 |     for _v in [1, 2, 3].iter() {}
    |               ^^^^^^^^^^^^^^^^ help: to write this more concisely, try: `&[1, 2, 3]`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:232:15
    |
232 |     for _v in [0; 32].iter() {}
    |               ^^^^^^^^^^^^^^ help: to write this more concisely, try: `&[0; 32]`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:237:15
    |
237 |     for _v in ll.iter() {}
    |               ^^^^^^^^^ help: to write this more concisely, try: `&ll`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:240:15
    |
240 |     for _v in vd.iter() {}
    |               ^^^^^^^^^ help: to write this more concisely, try: `&vd`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:243:15
    |
243 |     for _v in bh.iter() {}
    |               ^^^^^^^^^ help: to write this more concisely, try: `&bh`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:246:15
    |
246 |     for _v in hm.iter() {}
    |               ^^^^^^^^^ help: to write this more concisely, try: `&hm`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:249:15
    |
249 |     for _v in bt.iter() {}
    |               ^^^^^^^^^ help: to write this more concisely, try: `&bt`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:252:15
    |
252 |     for _v in hs.iter() {}
    |               ^^^^^^^^^ help: to write this more concisely, try: `&hs`

error: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
   --> $DIR/for_loop.rs:255:15
    |
255 |     for _v in bs.iter() {}
    |               ^^^^^^^^^ help: to write this more concisely, try: `&bs`

error: you are iterating over `Iterator::next()` which is an Option; this will compile but is probably not what you want
   --> $DIR/for_loop.rs:257:5
    |
257 |     for _v in vec.iter().next() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: you are collect()ing an iterator and throwing away the result. Consider using an explicit for loop to exhaust the iterator
   --> $DIR/for_loop.rs:264:5
    |
264 |     vec.iter().cloned().map(|x| out.push(x)).collect::<Vec<_>>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `-D unused-collect` implied by `-D warnings`

error: the variable `_index` is used as a loop counter. Consider using `for (_index, item) in &vec.enumerate()` or similar iterators
   --> $DIR/for_loop.rs:269:5
    |
269 | /     for _v in &vec {
270 | |         _index += 1
271 | |     }
    | |_____^
    |
    = note: `-D explicit-counter-loop` implied by `-D warnings`

error: the variable `_index` is used as a loop counter. Consider using `for (_index, item) in &vec.enumerate()` or similar iterators
   --> $DIR/for_loop.rs:275:5
    |
275 | /     for _v in &vec {
276 | |         _index += 1
277 | |     }
    | |_____^

error: you seem to want to iterate on a map's values
   --> $DIR/for_loop.rs:385:5
    |
385 | /     for (_, v) in &m {
386 | |         let _v = v;
387 | |     }
    | |_____^
    |
    = note: `-D for-kv-map` implied by `-D warnings`
help: use the corresponding method
    |
385 |     for v in m.values() {
    |         ^

error: you seem to want to iterate on a map's values
   --> $DIR/for_loop.rs:390:5
    |
390 | /     for (_, v) in &*m {
391 | |         let _v = v;
392 | |         // Here the `*` is not actually necesarry, but the test tests that we don't
393 | |         // suggest
394 | |         // `in *m.values()` as we used to
395 | |     }
    | |_____^
    |
help: use the corresponding method
    |
390 |     for v in (*m).values() {
    |         ^

error: you seem to want to iterate on a map's values
   --> $DIR/for_loop.rs:398:5
    |
398 | /     for (_, v) in &mut m {
399 | |         let _v = v;
400 | |     }
    | |_____^
    |
help: use the corresponding method
    |
398 |     for v in m.values_mut() {
    |         ^

error: you seem to want to iterate on a map's values
   --> $DIR/for_loop.rs:403:5
    |
403 | /     for (_, v) in &mut *m {
404 | |         let _v = v;
405 | |     }
    | |_____^
    |
help: use the corresponding method
    |
403 |     for v in (*m).values_mut() {
    |         ^

error: you seem to want to iterate on a map's keys
   --> $DIR/for_loop.rs:409:5
    |
409 | /     for (k, _value) in rm {
410 | |         let _k = k;
411 | |     }
    | |_____^
    |
help: use the corresponding method
    |
409 |     for k in rm.keys() {
    |         ^

error: it looks like you're manually copying between slices
   --> $DIR/for_loop.rs:462:5
    |
462 | /     for i in 0..src.len() {
463 | |         dst[i] = src[i];
464 | |     }
    | |_____^ help: try replacing the loop by: `dst[..src.len()].clone_from_slice(&src[..])`
    |
    = note: `-D manual-memcpy` implied by `-D warnings`

error: it looks like you're manually copying between slices
   --> $DIR/for_loop.rs:467:5
    |
467 | /     for i in 0..src.len() {
468 | |         dst[i + 10] = src[i];
469 | |     }
    | |_____^ help: try replacing the loop by: `dst[10..(src.len() + 10)].clone_from_slice(&src[..])`

error: it looks like you're manually copying between slices
   --> $DIR/for_loop.rs:472:5
    |
472 | /     for i in 0..src.len() {
473 | |         dst[i] = src[i + 10];
474 | |     }
    | |_____^ help: try replacing the loop by: `dst[..src.len()].clone_from_slice(&src[10..])`

error: it looks like you're manually copying between slices
   --> $DIR/for_loop.rs:477:5
    |
477 | /     for i in 11..src.len() {
478 | |         dst[i] = src[i - 10];
479 | |     }
    | |_____^ help: try replacing the loop by: `dst[11..src.len()].clone_from_slice(&src[(11 - 10)..(src.len() - 10)])`

error: it looks like you're manually copying between slices
   --> $DIR/for_loop.rs:482:5
    |
482 | /     for i in 0..dst.len() {
483 | |         dst[i] = src[i];
484 | |     }
    | |_____^ help: try replacing the loop by: `dst.clone_from_slice(&src[..dst.len()])`

error: it looks like you're manually copying between slices
   --> $DIR/for_loop.rs:495:5
    |
495 | /     for i in 10..256 {
496 | |         dst[i] = src[i - 5];
497 | |         dst2[i + 500] = src[i]
498 | |     }
    | |_____^
    |
help: try replacing the loop by
    |
495 |     dst[10..256].clone_from_slice(&src[(10 - 5)..(256 - 5)])
496 |     dst2[(10 + 500)..(256 + 500)].clone_from_slice(&src[10..256])
    |

error: it looks like you're manually copying between slices
   --> $DIR/for_loop.rs:507:5
    |
507 | /     for i in 10..LOOP_OFFSET {
508 | |         dst[i + LOOP_OFFSET] = src[i - some_var];
509 | |     }
    | |_____^ help: try replacing the loop by: `dst[(10 + LOOP_OFFSET)..(LOOP_OFFSET + LOOP_OFFSET)].clone_from_slice(&src[(10 - some_var)..(LOOP_OFFSET - some_var)])`

error: it looks like you're manually copying between slices
   --> $DIR/for_loop.rs:520:5
    |
520 | /     for i in 0..src_vec.len() {
521 | |         dst_vec[i] = src_vec[i];
522 | |     }
    | |_____^ help: try replacing the loop by: `dst_vec[..src_vec.len()].clone_from_slice(&src_vec[..])`

error: it looks like you're manually copying between slices
   --> $DIR/for_loop.rs:547:5
    |
547 | /     for i in 0..src.len() {
548 | |         dst[i] = src[i].clone();
549 | |     }
    | |_____^ help: try replacing the loop by: `dst[..src.len()].clone_from_slice(&src[..])`