Auto merge of #8992 - kyoto7250:fix_8753, r=flip1995

feat(fix): Do not lint if the target code is inside a loop

close #8753

we consider the following code.

```rust
fn main() {
    let vec = vec![1];
    let w: Vec<usize> = vec.iter().map(|i| i * i).collect();  // <- once.

    for i in 0..2 {
        let _ = w.contains(&i);
    }
}
```

and the clippy will issue the following warning.

```rust
warning: avoid using `collect()` when not needed
 --> src/main.rs:3:51
  |
3 |     let w: Vec<usize> = vec.iter().map(|i| i * i).collect();
  |                                                   ^^^^^^^
...
6 |         let _ = w.contains(&i);
  |                 -------------- the iterator could be used here instead
  |
  = note: `#[warn(clippy::needless_collect)]` on by default
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_collect
help: check if the original Iterator contains an element instead of collecting then checking
  |
3 ~
4 |
5 |     for i in 0..2 {
6 ~         let _ = vec.iter().map(|i| i * i).any(|x| x == i);
```

Rewrite the code as indicated.

```rust
fn main() {
    let vec = vec![1];

    for i in 0..2 {
        let _ = vec.iter().map(|i| i * i).any(|x| x == i);  // <- execute `map` every loop.
    }
}
```

this code is valid in the compiler, but, it is different from the code before the rewrite.
So, we should not lint, If `collect` is outside of a loop.

Thank you in advance.

---

changelog: Do not lint if the target code is inside a loop in `needless_collect`

0 files changed, 0 insertions, 0 deletions