rust/tests/ui/iter_nth.rs

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// aux-build:option_helpers.rs
#![warn(clippy::iter_nth)]
#[macro_use]
extern crate option_helpers;
use option_helpers::IteratorFalsePositives;
use std::collections::VecDeque;
/// Struct to generate false positives for things with `.iter()`.
#[derive(Copy, Clone)]
struct HasIter;
impl HasIter {
fn iter(self) -> IteratorFalsePositives {
IteratorFalsePositives { foo: 0 }
}
fn iter_mut(self) -> IteratorFalsePositives {
IteratorFalsePositives { foo: 0 }
}
}
/// Checks implementation of `ITER_NTH` lint.
fn iter_nth() {
let mut some_vec = vec![0, 1, 2, 3];
let mut boxed_slice: Box<[u8]> = Box::new([0, 1, 2, 3]);
let mut some_vec_deque: VecDeque<_> = some_vec.iter().cloned().collect();
{
// Make sure we lint `.iter()` for relevant types.
let bad_vec = some_vec.iter().nth(3);
let bad_slice = &some_vec[..].iter().nth(3);
let bad_boxed_slice = boxed_slice.iter().nth(3);
let bad_vec_deque = some_vec_deque.iter().nth(3);
}
{
// Make sure we lint `.iter_mut()` for relevant types.
let bad_vec = some_vec.iter_mut().nth(3);
}
{
let bad_slice = &some_vec[..].iter_mut().nth(3);
}
{
let bad_vec_deque = some_vec_deque.iter_mut().nth(3);
}
// Make sure we don't lint for non-relevant types.
let false_positive = HasIter;
let ok = false_positive.iter().nth(3);
let ok_mut = false_positive.iter_mut().nth(3);
}
fn main() {}