summaryrefslogtreecommitdiffstats
path: root/src/tools/clippy/tests/ui/needless_collect.fixed
blob: 2659ad384885e6a3e8efaea935716376a05e8667 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
// run-rustfix

#![allow(unused, clippy::suspicious_map, clippy::iter_count)]

use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, LinkedList};

#[warn(clippy::needless_collect)]
#[allow(unused_variables, clippy::iter_cloned_collect, clippy::iter_next_slice)]
fn main() {
    let sample = [1; 5];
    let len = sample.iter().count();
    if sample.iter().next().is_none() {
        // Empty
    }
    sample.iter().cloned().any(|x| x == 1);
    // #7164 HashMap's and BTreeMap's `len` usage should not be linted
    sample.iter().map(|x| (x, x)).collect::<HashMap<_, _>>().len();
    sample.iter().map(|x| (x, x)).collect::<BTreeMap<_, _>>().len();

    sample.iter().map(|x| (x, x)).next().is_none();
    sample.iter().map(|x| (x, x)).next().is_none();

    // Notice the `HashSet`--this should not be linted
    sample.iter().collect::<HashSet<_>>().len();
    // Neither should this
    sample.iter().collect::<BTreeSet<_>>().len();

    sample.iter().count();
    sample.iter().next().is_none();
    sample.iter().cloned().any(|x| x == 1);
    sample.iter().any(|x| x == &1);

    // `BinaryHeap` doesn't have `contains` method
    sample.iter().count();
    sample.iter().next().is_none();

    // Don't lint string from str
    let _ = ["", ""].into_iter().collect::<String>().is_empty();

    let _ = sample.iter().next().is_none();
    let _ = sample.iter().any(|x| x == &0);

    struct VecWrapper<T>(Vec<T>);
    impl<T> core::ops::Deref for VecWrapper<T> {
        type Target = Vec<T>;
        fn deref(&self) -> &Self::Target {
            &self.0
        }
    }
    impl<T> IntoIterator for VecWrapper<T> {
        type IntoIter = <Vec<T> as IntoIterator>::IntoIter;
        type Item = <Vec<T> as IntoIterator>::Item;
        fn into_iter(self) -> Self::IntoIter {
            self.0.into_iter()
        }
    }
    impl<T> FromIterator<T> for VecWrapper<T> {
        fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
            Self(Vec::from_iter(iter))
        }
    }

    let _ = sample.iter().next().is_none();
    let _ = sample.iter().any(|x| x == &0);
}