//@run-rustfix //@aux-build: proc_macros.rs:proc-macro #![allow(dead_code, unused_variables)] extern crate proc_macros; use proc_macros::with_span; fn main() {} mod should_lint { fn one_help() { let a = &12; let b = &*a; let b = &mut &*bar(&12); } fn bar(x: &u32) -> &u32 { x } } // this mod explains why we should not lint `&mut &* (&T)` mod should_not_lint1 { fn foo(x: &mut &u32) { *x = &1; } fn main() { let mut x = &0; foo(&mut &*x); // should not lint assert_eq!(*x, 0); foo(&mut x); assert_eq!(*x, 1); } } // similar to should_not_lint1 mod should_not_lint2 { struct S<'a> { a: &'a u32, b: u32, } fn main() { let s = S { a: &1, b: 1 }; let x = &mut &*s.a; *x = &2; } } with_span!( span fn just_returning(x: &u32) -> &u32 { x } fn dont_lint_proc_macro() { let a = &mut &*just_returning(&12); } ); // this mod explains why we should not lint `& &* (&T)` mod false_negative { fn foo() { let x = &12; let addr_x = &x as *const _ as usize; let addr_y = &&*x as *const _ as usize; // assert ok // let addr_y = &x as *const _ as usize; // assert fail assert_ne!(addr_x, addr_y); } }