mirror of
https://github.com/rust-lang/rust-clippy
synced 2024-11-24 05:33:27 +00:00
131 lines
3.4 KiB
Rust
131 lines
3.4 KiB
Rust
#![allow(unused, clippy::needless_lifetimes)]
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#![warn(
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clippy::style,
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clippy::mem_replace_option_with_none,
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clippy::mem_replace_with_default
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)]
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use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, LinkedList, VecDeque};
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use std::mem;
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fn replace_option_with_none() {
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let mut an_option = Some(1);
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let _ = an_option.take();
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let an_option = &mut Some(1);
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let _ = an_option.take();
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}
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fn replace_with_default() {
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let mut s = String::from("foo");
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let _ = std::mem::take(&mut s);
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let s = &mut String::from("foo");
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let _ = std::mem::take(s);
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let _ = std::mem::take(s);
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let mut v = vec![123];
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let _ = std::mem::take(&mut v);
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let _ = std::mem::take(&mut v);
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let _ = std::mem::take(&mut v);
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let _ = std::mem::take(&mut v);
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let mut hash_map: HashMap<i32, i32> = HashMap::new();
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let _ = std::mem::take(&mut hash_map);
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let mut btree_map: BTreeMap<i32, i32> = BTreeMap::new();
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let _ = std::mem::take(&mut btree_map);
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let mut vd: VecDeque<i32> = VecDeque::new();
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let _ = std::mem::take(&mut vd);
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let mut hash_set: HashSet<&str> = HashSet::new();
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let _ = std::mem::take(&mut hash_set);
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let mut btree_set: BTreeSet<&str> = BTreeSet::new();
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let _ = std::mem::take(&mut btree_set);
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let mut list: LinkedList<i32> = LinkedList::new();
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let _ = std::mem::take(&mut list);
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let mut binary_heap: BinaryHeap<i32> = BinaryHeap::new();
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let _ = std::mem::take(&mut binary_heap);
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let mut tuple = (vec![1, 2], BinaryHeap::<i32>::new());
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let _ = std::mem::take(&mut tuple);
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let mut refstr = "hello";
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let _ = std::mem::take(&mut refstr);
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let mut slice: &[i32] = &[1, 2, 3];
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let _ = std::mem::take(&mut slice);
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}
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// lint is disabled for primitives because in this case `take`
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// has no clear benefit over `replace` and sometimes is harder to read
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fn dont_lint_primitive() {
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let mut pbool = true;
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let _ = std::mem::replace(&mut pbool, false);
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let mut pint = 5;
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let _ = std::mem::replace(&mut pint, 0);
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}
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// lint is disabled for expressions that are not used because changing to `take` is not the
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// recommended fix. Additionally, the `replace` is #[must_use], so that lint will provide
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// the correct suggestion
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fn dont_lint_not_used() {
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let mut s = String::from("foo");
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std::mem::replace(&mut s, String::default());
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}
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fn main() {
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replace_option_with_none();
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replace_with_default();
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dont_lint_primitive();
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}
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#[clippy::msrv = "1.39"]
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fn msrv_1_39() {
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let mut s = String::from("foo");
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let _ = std::mem::replace(&mut s, String::default());
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}
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#[clippy::msrv = "1.40"]
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fn msrv_1_40() {
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let mut s = String::from("foo");
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let _ = std::mem::take(&mut s);
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}
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fn issue9824() {
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struct Foo<'a>(Option<&'a str>);
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impl<'a> std::ops::Deref for Foo<'a> {
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type Target = Option<&'a str>;
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fn deref(&self) -> &Self::Target {
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&self.0
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}
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}
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impl<'a> std::ops::DerefMut for Foo<'a> {
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fn deref_mut(&mut self) -> &mut Self::Target {
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&mut self.0
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}
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}
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struct Bar {
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opt: Option<u8>,
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val: String,
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}
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let mut f = Foo(Some("foo"));
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let mut b = Bar {
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opt: Some(1),
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val: String::from("bar"),
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};
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// replace option with none
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let _ = f.0.take();
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let _ = (*f).take();
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let _ = b.opt.take();
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// replace with default
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let _ = std::mem::take(&mut b.val);
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}
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