rust-clippy/tests/ui/vec.rs

// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#![warn(clippy::useless_vec)]

#[derive(Debug)]
struct NonCopy;

fn on_slice(_: &[u8]) {}
#[allow(clippy::ptr_arg)]
fn on_vec(_: &Vec<u8>) {}

struct Line {
    length: usize,
}

impl Line {
    fn length(&self) -> usize {
        self.length
    }
}

fn main() {
    on_slice(&vec![]);
    on_slice(&[]);

    on_slice(&vec![1, 2]);
    on_slice(&[1, 2]);

    on_slice(&vec![1, 2]);
    on_slice(&[1, 2]);
    #[rustfmt::skip]
    on_slice(&vec!(1, 2));
    on_slice(&[1, 2]);

    on_slice(&vec![1; 2]);
    on_slice(&[1; 2]);

    on_vec(&vec![]);
    on_vec(&vec![1, 2]);
    on_vec(&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()]);

    for a in vec![1, 2, 3] {
        println!("{:?}", a);
    }

    for a in vec![NonCopy, NonCopy] {
        println!("{:?}", a);
    }
}