//@run-rustfix // rustfix-only-machine-applicable #![feature(lint_reasons)] #![warn(clippy::redundant_clone)] #![allow(clippy::drop_non_drop, clippy::implicit_clone, clippy::uninlined_format_args)] use std::ffi::OsString; use std::path::Path; fn main() { let _s = ["lorem", "ipsum"].join(" ").to_string(); let s = String::from("foo"); let _s = s.clone(); let s = String::from("foo"); let _s = s.to_string(); let s = String::from("foo"); let _s = s.to_owned(); let _s = Path::new("/a/b/").join("c").to_owned(); let _s = Path::new("/a/b/").join("c").to_path_buf(); let _s = OsString::new().to_owned(); let _s = OsString::new().to_os_string(); // Check that lint level works #[allow(clippy::redundant_clone)] let _s = String::new().to_string(); // Check that lint level works #[expect(clippy::redundant_clone)] let _s = String::new().to_string(); let tup = (String::from("foo"),); let _t = tup.0.clone(); let tup_ref = &(String::from("foo"),); let _s = tup_ref.0.clone(); // this `.clone()` cannot be removed { let x = String::new(); let y = &x; let _x = x.clone(); // ok; `x` is borrowed by `y` let _ = y.len(); } let x = (String::new(),); let _ = Some(String::new()).unwrap_or_else(|| x.0.clone()); // ok; closure borrows `x` with_branch(Alpha, true); cannot_double_move(Alpha); cannot_move_from_type_with_drop(); borrower_propagation(); not_consumed(); issue_5405(); manually_drop(); clone_then_move_cloned(); hashmap_neg(); false_negative_5707(); } #[derive(Clone)] struct Alpha; fn with_branch(a: Alpha, b: bool) -> (Alpha, Alpha) { if b { (a.clone(), a.clone()) } else { (Alpha, a) } } fn cannot_double_move(a: Alpha) -> (Alpha, Alpha) { (a.clone(), a) } struct TypeWithDrop { x: String, } impl Drop for TypeWithDrop { fn drop(&mut self) {} } fn cannot_move_from_type_with_drop() -> String { let s = TypeWithDrop { x: String::new() }; s.x.clone() // removing this `clone()` summons E0509 } fn borrower_propagation() { let s = String::new(); let t = String::new(); { fn b() -> bool { unimplemented!() } let _u = if b() { &s } else { &t }; // ok; `s` and `t` are possibly borrowed let _s = s.clone(); let _t = t.clone(); } { let _u = || s.len(); let _v = [&t; 32]; let _s = s.clone(); // ok let _t = t.clone(); // ok } { let _u = { let u = Some(&s); let _ = s.clone(); // ok u }; let _s = s.clone(); // ok } { use std::convert::identity as id; let _u = id(id(&s)); let _s = s.clone(); // ok, `u` borrows `s` } let _s = s.clone(); let _t = t.clone(); #[derive(Clone)] struct Foo { x: usize, } { let f = Foo { x: 123 }; let _x = Some(f.x); let _f = f.clone(); } { let f = Foo { x: 123 }; let _x = &f.x; let _f = f.clone(); // ok } } fn not_consumed() { let x = std::path::PathBuf::from("home"); let y = x.clone().join("matthias"); // join() creates a new owned PathBuf, does not take a &mut to x variable, thus the .clone() is // redundant. (It also does not consume the PathBuf) println!("x: {:?}, y: {:?}", x, y); let mut s = String::new(); s.clone().push_str("foo"); // OK, removing this `clone()` will change the behavior. s.push_str("bar"); assert_eq!(s, "bar"); let t = Some(s); // OK if let Some(x) = t.clone() { println!("{}", x); } if let Some(x) = t { println!("{}", x); } } #[allow(clippy::clone_on_copy)] fn issue_5405() { let a: [String; 1] = [String::from("foo")]; let _b: String = a[0].clone(); let c: [usize; 2] = [2, 3]; let _d: usize = c[1].clone(); } fn manually_drop() { use std::mem::ManuallyDrop; use std::sync::Arc; let a = ManuallyDrop::new(Arc::new("Hello!".to_owned())); let _ = a.clone(); // OK let p: *const String = Arc::into_raw(ManuallyDrop::into_inner(a)); unsafe { Arc::from_raw(p); Arc::from_raw(p); } } fn clone_then_move_cloned() { // issue #5973 let x = Some(String::new()); // ok, x is moved while the clone is in use. assert_eq!(x.clone(), None, "not equal {}", x.unwrap()); // issue #5595 fn foo(_: &Alpha, _: F) {} let x = Alpha; // ok, data is moved while the clone is in use. foo(&x.clone(), move || { let _ = x; }); // issue #6998 struct S(String); impl S { fn m(&mut self) {} } let mut x = S(String::new()); x.0.clone().chars().for_each(|_| x.m()); } fn hashmap_neg() { // issue 5707 use std::collections::HashMap; use std::path::PathBuf; let p = PathBuf::from("/"); let mut h: HashMap<&str, &str> = HashMap::new(); h.insert("orig-p", p.to_str().unwrap()); let mut q = p.clone(); q.push("foo"); println!("{:?} {}", h, q.display()); } fn false_negative_5707() { fn foo(_x: &Alpha, _y: &mut Alpha) {} let x = Alpha; let mut y = Alpha; foo(&x, &mut y); let _z = x.clone(); // pr 7346 can't lint on `x` drop(y); }