#![allow(unused, clippy::many_single_char_names)] #![warn(clippy::ptr_arg)] use std::borrow::Cow; fn do_vec(x: &Vec) { //Nothing here } fn do_vec_mut(x: &mut Vec) { // no error here //Nothing here } fn do_str(x: &String) { //Nothing here either } fn do_str_mut(x: &mut String) { // no error here //Nothing here either } fn main() {} trait Foo { type Item; fn do_vec(x: &Vec); fn do_item(x: &Self::Item); } struct Bar; // no error, in trait impl (#425) impl Foo for Bar { type Item = Vec; fn do_vec(x: &Vec) {} fn do_item(x: &Vec) {} } fn cloned(x: &Vec) -> Vec { let e = x.clone(); let f = e.clone(); // OK let g = x; let h = g.clone(); // Alas, we cannot reliably detect this without following data. let i = (e).clone(); x.clone() } fn str_cloned(x: &String) -> String { let a = x.clone(); let b = x.clone(); let c = b.clone(); let d = a.clone().clone().clone(); x.clone() } fn false_positive_capacity(x: &Vec, y: &String) { let a = x.capacity(); let b = y.clone(); let c = y.as_str(); } fn false_positive_capacity_too(x: &String) -> String { if x.capacity() > 1024 { panic!("Too large!"); } x.clone() } #[allow(dead_code)] fn test_cow_with_ref(c: &Cow<[i32]>) {} #[allow(dead_code)] fn test_cow(c: Cow<[i32]>) { let _c = c; } trait Foo2 { fn do_string(&self); } // no error for &self references where self is of type String (#2293) impl Foo2 for String { fn do_string(&self) {} }