#![no_std] #![feature(lang_items, start, libc)] #![crate_type = "lib"] use core::panic::PanicInfo; #[warn(clippy::all)] fn main() { let mut a = 42; let mut b = 1337; a = b; //~^ ERROR: this looks like you are trying to swap `a` and `b` //~| NOTE: or maybe you should use `core::mem::replace`? b = a; }