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#![allow(unused, clippy::map_identity)]
#![warn(clippy::unused_enumerate_index)]
use std::iter::Enumerate;
fn get_enumerate() -> Enumerate<std::vec::IntoIter<i32>> {
vec![1].into_iter().enumerate()
}
fn main() {
let v = [1, 2, 3];
for (_, x) in v.iter().enumerate() {
//~^ unused_enumerate_index
println!("{x}");
}
struct Dummy1;
impl Dummy1 {
fn enumerate(self) -> Vec<usize> {
vec![]
}
}
let dummy = Dummy1;
for x in dummy.enumerate() {
println!("{x}");
}
struct Dummy2;
impl Dummy2 {
fn enumerate(self) -> Enumerate<std::vec::IntoIter<usize>> {
vec![1, 2].into_iter().enumerate()
}
}
let dummy = Dummy2;
for (_, x) in dummy.enumerate() {
println!("{x}");
}
let mut with_used_iterator = [1, 2, 3].into_iter().enumerate();
with_used_iterator.next();
for (_, x) in with_used_iterator {
println!("{x}");
}
struct Dummy3(std::vec::IntoIter<usize>);
impl Iterator for Dummy3 {
type Item = usize;
fn next(&mut self) -> Option<Self::Item> {
self.0.next()
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.0.size_hint()
}
}
let dummy = Dummy3(vec![1, 2, 3].into_iter());
for (_, x) in dummy.enumerate() {
//~^ unused_enumerate_index
println!("{x}");
}
let _ = vec![1, 2, 3].into_iter().enumerate().map(|(_, x)| println!("{x}"));
//~^ unused_enumerate_index
let p = vec![1, 2, 3].into_iter().enumerate();
//~^ unused_enumerate_index
p.map(|(_, x)| println!("{x}"));
// This shouldn't trigger the lint. `get_enumerate` may come from an external library on which we
// have no control.
let p = get_enumerate();
p.map(|(_, x)| println!("{x}"));
// This shouldn't trigger the lint. The `enumerate` call is in a different context.
macro_rules! mac {
() => {
[1].iter().enumerate()
};
}
_ = mac!().map(|(_, v)| v);
macro_rules! mac2 {
() => {
[1].iter()
};
}
_ = mac2!().enumerate().map(|(_, _v)| {});
//~^ unused_enumerate_index
// This shouldn't trigger the lint because of the `allow`.
#[allow(clippy::unused_enumerate_index)]
let v = [1].iter().enumerate();
v.map(|(_, _x)| {});
// This should keep the explicit type of `x`.
let v = [1, 2, 3].iter().copied().enumerate();
//~^ unused_enumerate_index
let x = v.map(|(_, x): (usize, i32)| x).sum::<i32>();
assert_eq!(x, 6);
// This should keep the explicit type of `x`.
let v = [1, 2, 3].iter().copied().enumerate();
//~^ unused_enumerate_index
let x = v.map(|(_, x): (_, i32)| x).sum::<i32>();
assert_eq!(x, 6);
let v = [1, 2, 3].iter().copied().enumerate();
//~^ unused_enumerate_index
let x = v.map(|(_, x)| x).sum::<i32>();
assert_eq!(x, 6);
}
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