| static static_x: i32 = 1; |
| static mut static_x_mut: i32 = 1; |
| |
| fn main() { |
| let x = 1; |
| let mut x_mut = 1; |
| |
| { |
| // borrow of local |
| let _y1 = &mut x; //~ ERROR [E0596] |
| let _y2 = &mut x_mut; // No error |
| } |
| |
| { |
| // borrow of static |
| let _y1 = &mut static_x; //~ ERROR [E0596] |
| unsafe { |
| let _y2 = &mut static_x_mut; |
| //~^ WARN mutable reference to mutable static is discouraged [static_mut_refs] |
| } |
| } |
| |
| { |
| // borrow of deref to box |
| let box_x = Box::new(1); |
| let mut box_x_mut = Box::new(1); |
| |
| let _y1 = &mut *box_x; //~ ERROR [E0596] |
| let _y2 = &mut *box_x_mut; // No error |
| } |
| |
| { |
| // borrow of deref to reference |
| let ref_x = &x; |
| let ref_x_mut = &mut x_mut; |
| |
| let _y1 = &mut *ref_x; //~ ERROR [E0596] |
| let _y2 = &mut *ref_x_mut; // No error |
| } |
| |
| { |
| // borrow of deref to pointer |
| let ptr_x: *const _ = &x; |
| let ptr_mut_x: *mut _ = &mut x_mut; |
| |
| unsafe { |
| let _y1 = &mut *ptr_x; //~ ERROR [E0596] |
| let _y2 = &mut *ptr_mut_x; // No error |
| } |
| } |
| |
| { |
| // borrowing mutably through an immutable reference |
| struct Foo<'a> { |
| f: &'a mut i32, |
| g: &'a i32, |
| }; |
| let mut foo = Foo { f: &mut x_mut, g: &x }; |
| let foo_ref = &foo; |
| let _y = &mut *foo_ref.f; //~ ERROR [E0596] |
| } |
| } |