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#![allow(unused, clippy::needless_lifetimes)]
#![warn(
clippy::style,
clippy::mem_replace_option_with_none,
clippy::mem_replace_with_default
)]
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, LinkedList, VecDeque};
use std::mem;
fn replace_option_with_none() {
let mut an_option = Some(1);
let _ = an_option.take();
//~^ mem_replace_option_with_none
let an_option = &mut Some(1);
let _ = an_option.take();
//~^ mem_replace_option_with_none
}
fn replace_with_default() {
let mut s = String::from("foo");
let _ = std::mem::take(&mut s);
//~^ mem_replace_with_default
let _ = std::mem::take(&mut s);
//~^ mem_replace_with_default
let s = &mut String::from("foo");
let _ = std::mem::take(s);
//~^ mem_replace_with_default
let _ = std::mem::take(s);
//~^ mem_replace_with_default
let _ = std::mem::take(s);
//~^ mem_replace_with_default
let mut v = vec![123];
let _ = std::mem::take(&mut v);
//~^ mem_replace_with_default
let _ = std::mem::take(&mut v);
//~^ mem_replace_with_default
let _ = std::mem::take(&mut v);
//~^ mem_replace_with_default
let _ = std::mem::take(&mut v);
//~^ mem_replace_with_default
let mut hash_map: HashMap<i32, i32> = HashMap::new();
let _ = std::mem::take(&mut hash_map);
//~^ mem_replace_with_default
let mut btree_map: BTreeMap<i32, i32> = BTreeMap::new();
let _ = std::mem::take(&mut btree_map);
//~^ mem_replace_with_default
let mut vd: VecDeque<i32> = VecDeque::new();
let _ = std::mem::take(&mut vd);
//~^ mem_replace_with_default
let mut hash_set: HashSet<&str> = HashSet::new();
let _ = std::mem::take(&mut hash_set);
//~^ mem_replace_with_default
let mut btree_set: BTreeSet<&str> = BTreeSet::new();
let _ = std::mem::take(&mut btree_set);
//~^ mem_replace_with_default
let mut list: LinkedList<i32> = LinkedList::new();
let _ = std::mem::take(&mut list);
//~^ mem_replace_with_default
let mut binary_heap: BinaryHeap<i32> = BinaryHeap::new();
let _ = std::mem::take(&mut binary_heap);
//~^ mem_replace_with_default
let mut tuple = (vec![1, 2], BinaryHeap::<i32>::new());
let _ = std::mem::take(&mut tuple);
//~^ mem_replace_with_default
let mut refstr = "hello";
let _ = std::mem::take(&mut refstr);
//~^ mem_replace_with_default
let mut slice: &[i32] = &[1, 2, 3];
let _ = std::mem::take(&mut slice);
//~^ mem_replace_with_default
}
// lint is disabled for primitives because in this case `take`
// has no clear benefit over `replace` and sometimes is harder to read
fn dont_lint_primitive() {
let mut pbool = true;
let _ = std::mem::replace(&mut pbool, false);
let mut pint = 5;
let _ = std::mem::replace(&mut pint, 0);
}
// lint is disabled for expressions that are not used because changing to `take` is not the
// recommended fix. Additionally, the `replace` is #[must_use], so that lint will provide
// the correct suggestion
fn dont_lint_not_used() {
let mut s = String::from("foo");
std::mem::replace(&mut s, String::default());
}
fn main() {
replace_option_with_none();
replace_with_default();
dont_lint_primitive();
}
#[clippy::msrv = "1.39"]
fn msrv_1_39() {
let mut s = String::from("foo");
let _ = std::mem::replace(&mut s, String::default());
}
#[clippy::msrv = "1.40"]
fn msrv_1_40() {
let mut s = String::from("foo");
let _ = std::mem::take(&mut s);
//~^ mem_replace_with_default
}
fn issue9824() {
struct Foo<'a>(Option<&'a str>);
impl<'a> std::ops::Deref for Foo<'a> {
type Target = Option<&'a str>;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl<'a> std::ops::DerefMut for Foo<'a> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0
}
}
struct Bar {
opt: Option<u8>,
val: String,
}
let mut f = Foo(Some("foo"));
let mut b = Bar {
opt: Some(1),
val: String::from("bar"),
};
// replace option with none
let _ = f.0.take();
//~^ mem_replace_option_with_none
let _ = (*f).take();
//~^ mem_replace_option_with_none
let _ = b.opt.take();
//~^ mem_replace_option_with_none
// replace with default
let _ = std::mem::take(&mut b.val);
//~^ mem_replace_with_default
}
#[clippy::msrv = "1.31"]
fn mem_replace_option_with_some() {
let mut an_option = Some(0);
let replaced = an_option.replace(1);
//~^ ERROR: replacing an `Option` with `Some(..)`
let mut an_option = &mut Some(0);
let replaced = an_option.replace(1);
//~^ ERROR: replacing an `Option` with `Some(..)`
let (mut opt1, mut opt2) = (Some(0), Some(0));
let b = true;
let replaced = (if b { &mut opt1 } else { &mut opt2 }).replace(1);
//~^ ERROR: replacing an `Option` with `Some(..)`
}
#[clippy::msrv = "1.30"]
fn mem_replace_option_with_some_bad_msrv() {
let mut an_option = Some(0);
let replaced = mem::replace(&mut an_option, Some(1));
}
|
