#![warn(clippy::clone_on_ref_ptr)] #![allow(unused)] use std::cell::RefCell; use std::collections::HashSet; use std::collections::VecDeque; use std::rc::{self, Rc}; use std::sync::{self, Arc}; trait SomeTrait {} struct SomeImpl; impl SomeTrait for SomeImpl {} fn main() {} fn clone_on_copy() { 42.clone(); vec![1].clone(); // ok, not a Copy type Some(vec![1]).clone(); // ok, not a Copy type (&42).clone(); let rc = RefCell::new(0); rc.borrow().clone(); // Issue #4348 let mut x = 43; let _ = &x.clone(); // ok, getting a ref 'a'.clone().make_ascii_uppercase(); // ok, clone and then mutate } fn clone_on_ref_ptr() { let rc = Rc::new(true); let arc = Arc::new(true); let rcweak = Rc::downgrade(&rc); let arc_weak = Arc::downgrade(&arc); rc.clone(); Rc::clone(&rc); arc.clone(); Arc::clone(&arc); rcweak.clone(); rc::Weak::clone(&rcweak); arc_weak.clone(); sync::Weak::clone(&arc_weak); let x = Arc::new(SomeImpl); let _: Arc<dyn SomeTrait> = x.clone(); } fn clone_on_copy_generic<T: Copy>(t: T) { t.clone(); Some(t).clone(); } fn clone_on_double_ref() { let x = vec![1]; let y = &&x; let z: &Vec<_> = y.clone(); println!("{:p} {:p}", *y, z); } fn iter_clone_collect() { let v = [1, 2, 3, 4, 5]; let v2: Vec<isize> = v.iter().cloned().collect(); let v3: HashSet<isize> = v.iter().cloned().collect(); let v4: VecDeque<isize> = v.iter().cloned().collect(); // Handle macro expansion in suggestion let _: Vec<isize> = vec![1, 2, 3].iter().cloned().collect(); // Issue #3704 unsafe { let _: Vec<u8> = std::ffi::CStr::from_ptr(std::ptr::null()) .to_bytes() .iter() .cloned() .collect(); } } mod many_derefs { struct A; struct B; struct C; struct D; #[derive(Copy, Clone)] struct E; macro_rules! impl_deref { ($src:ident, $dst:ident) => { impl std::ops::Deref for $src { type Target = $dst; fn deref(&self) -> &Self::Target { &$dst } } }; } impl_deref!(A, B); impl_deref!(B, C); impl_deref!(C, D); impl std::ops::Deref for D { type Target = &'static E; fn deref(&self) -> &Self::Target { &&E } } fn go1() { let a = A; let _: E = a.clone(); let _: E = *****a; } }