//@run-rustfix #![warn(clippy::useless_vec)] #![allow(clippy::nonstandard_macro_braces, clippy::uninlined_format_args, unused)] use std::rc::Rc; struct StructWithVec { _x: Vec, } fn on_slice(_: &[u8]) {} fn on_mut_slice(_: &mut [u8]) {} #[allow(clippy::ptr_arg)] fn on_vec(_: &Vec) {} fn on_mut_vec(_: &mut Vec) {} struct Line { length: usize, } impl Line { fn length(&self) -> usize { self.length } } fn main() { on_slice(&[]); on_slice(&[]); on_mut_slice(&mut []); on_slice(&[1, 2]); on_slice(&[1, 2]); on_mut_slice(&mut [1, 2]); on_slice(&[1, 2]); on_slice(&[1, 2]); on_mut_slice(&mut [1, 2]); #[rustfmt::skip] on_slice(&[1, 2]); on_slice(&[1, 2]); on_mut_slice(&mut [1, 2]); on_slice(&[1; 2]); on_slice(&[1; 2]); on_mut_slice(&mut [1; 2]); on_vec(&vec![]); on_vec(&vec![1, 2]); on_vec(&vec![1; 2]); on_mut_vec(&mut vec![]); on_mut_vec(&mut vec![1, 2]); on_mut_vec(&mut vec![1; 2]); // Now with non-constant expressions let line = Line { length: 2 }; on_slice(&vec![2; line.length]); on_slice(&vec![2; line.length()]); on_mut_slice(&mut vec![2; line.length]); on_mut_slice(&mut vec![2; line.length()]); on_vec(&vec![1; 201]); // Ok, size of `vec` higher than `too_large_for_stack` on_mut_vec(&mut vec![1; 201]); // Ok, size of `vec` higher than `too_large_for_stack` // Ok for a in vec![1; 201] { println!("{:?}", a); } // Do lint let mut x = [1, 2, 3]; x.fill(123); dbg!(x[0]); dbg!(x.len()); dbg!(x.iter().sum::()); let _x: &[i32] = &[1, 2, 3]; for _ in [1, 2, 3] {} // Don't lint let x = vec![1, 2, 3]; let _v: Vec = x; let x = vec![1, 2, 3]; let _s = StructWithVec { _x: x }; // Explicit type annotation would make the change to [1, 2, 3] // a compile error. let _x: Vec = vec![1, 2, 3]; // Calling a Vec method through a mutable reference let mut x = vec![1, 2, 3]; let re = &mut x; re.push(4); // Comparing arrays whose length is not equal is a compile error let x = vec![1, 2, 3]; let y = vec![1, 2, 3, 4]; dbg!(x == y); // Non-copy types let _x = vec![String::new(); 10]; #[allow(clippy::rc_clone_in_vec_init)] let _x = vec![Rc::new(1); 10]; // Too large let _x = vec![1; 201]; } #[clippy::msrv = "1.53"] fn above() { for a in [1, 2, 3] { let _: usize = a; } for a in [String::new(), String::new()] { let _: String = a; } } #[clippy::msrv = "1.52"] fn below() { for a in vec![1, 2, 3] { let _: usize = a; } for a in vec![String::new(), String::new()] { let _: String = a; } }