src/tools/clippy/tests/ui/cmp_null.rs


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#![warn(clippy::cmp_null)]
#![allow(unused_mut)]

use std::ptr;

fn main() {
    let x = 0;
    let p: *const usize = &x;
    if p == ptr::null() {
        //~^ ERROR: comparing with null is better expressed by the `.is_null()` method
        //~| NOTE: `-D clippy::cmp-null` implied by `-D warnings`
        println!("This is surprising!");
    }
    if ptr::null() == p {
        //~^ ERROR: comparing with null is better expressed by the `.is_null()` method
        println!("This is surprising!");
    }

    let mut y = 0;
    let mut m: *mut usize = &mut y;
    if m == ptr::null_mut() {
        //~^ ERROR: comparing with null is better expressed by the `.is_null()` method
        println!("This is surprising, too!");
    }
    if ptr::null_mut() == m {
        //~^ ERROR: comparing with null is better expressed by the `.is_null()` method
        println!("This is surprising, too!");
    }

    let _ = x as *const () == ptr::null();
    //~^ ERROR: comparing with null is better expressed by the `.is_null()` method
}