e440065a0f
key idea: for `f` in `.map(f)` and `.for_each(f)`: 1. `f` must be a closure with one parameter 2. don't lint if mutable paramter in clsure `f`: `|mut x| ...` 3. don't lint if parameter is moved
83 lines
2.4 KiB
Rust
83 lines
2.4 KiB
Rust
#![warn(clippy::iter_overeager_cloned, clippy::redundant_clone, clippy::filter_next)]
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#![allow(dead_code, clippy::let_unit_value, clippy::useless_vec)]
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fn main() {
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let vec = vec!["1".to_string(), "2".to_string(), "3".to_string()];
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let _: Option<String> = vec.iter().last().cloned();
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let _: Option<String> = vec.iter().chain(vec.iter()).next().cloned();
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let _: usize = vec.iter().filter(|x| x == &"2").count();
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let _: Vec<_> = vec.iter().take(2).cloned().collect();
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let _: Vec<_> = vec.iter().skip(2).cloned().collect();
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let _ = vec.iter().filter(|x| x == &"2").nth(2).cloned();
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let _ = [Some(Some("str".to_string())), Some(Some("str".to_string()))]
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.iter()
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.flatten().cloned();
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let _ = vec.iter().filter(|&x| x.starts_with('2')).cloned();
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let _ = vec.iter().find(|&x| x == "2").cloned();
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{
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let f = |x: &String| x.starts_with('2');
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let _ = vec.iter().filter(|&x| f(x)).cloned();
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let _ = vec.iter().find(|&x| f(x)).cloned();
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}
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{
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let vec: Vec<(String, String)> = vec![];
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let f = move |x: &(String, String)| x.0.starts_with('2');
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let _ = vec.iter().filter(|&x| f(x)).cloned();
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let _ = vec.iter().find(|&x| f(x)).cloned();
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}
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fn test_move<'a>(
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iter: impl Iterator<Item = &'a (&'a u32, String)> + 'a,
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target: String,
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) -> impl Iterator<Item = (&'a u32, String)> + 'a {
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iter.filter(move |&(&a, b)| a == 1 && b == &target).cloned()
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}
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{
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#[derive(Clone)]
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struct S<'a> {
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a: &'a u32,
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b: String,
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}
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fn bar<'a>(iter: impl Iterator<Item = &'a S<'a>> + 'a, target: String) -> impl Iterator<Item = S<'a>> + 'a {
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iter.filter(move |&S { a, b }| **a == 1 && b == &target).cloned()
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}
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}
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let _ = vec.iter().map(|x| x.len());
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// This would fail if changed.
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let _ = vec.iter().cloned().map(|x| x + "2");
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let _ = vec.iter().for_each(|x| assert!(!x.is_empty()));
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// Not implemented yet
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let _ = vec.iter().cloned().all(|x| x.len() == 1);
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// Not implemented yet
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let _ = vec.iter().cloned().any(|x| x.len() == 1);
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// Should probably stay as it is.
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let _ = [0, 1, 2, 3, 4].iter().cloned().take(10);
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// `&Range<_>` doesn't implement `IntoIterator`
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let _ = [0..1, 2..5].iter().cloned().flatten();
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}
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// #8527
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fn cloned_flatten(x: Option<&Option<String>>) -> Option<String> {
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x.cloned().flatten()
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}
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