rust/tests/ui/dereference.rs

#![allow(unused_variables, clippy::many_single_char_names, clippy::clone_double_ref)]
#![warn(clippy::explicit_deref_method)]

use std::ops::{Deref, DerefMut};

fn main() {
    let a: &mut String = &mut String::from("foo");

    // these should require linting
    let b: &str = a.deref();

    let b: &mut str = a.deref_mut();

    let b: String = a.deref().clone();

    let b: usize = a.deref_mut().len();

    let b: &usize = &a.deref().len();

    // only first deref should get linted here
    let b: &str = a.deref().deref();

    // both derefs should get linted here
    let b: String = format!("{}, {}", a.deref(), a.deref());

    // these should not require linting

    let b: &str = &*a;

    let b: &mut str = &mut *a;

    macro_rules! expr_deref {
        ($body:expr) => {
            $body.deref()
        };
    }
    let b: &str = expr_deref!(a);
}