error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:15:16
   |
LL |     let _num = &mut *(num as *const i32 as *mut i32);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `#[deny(invalid_reference_casting)]` on by default

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:17:16
   |
LL |     let _num = &mut *(num as *const i32).cast_mut();
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:19:16
   |
LL |     let _num = &mut *std::ptr::from_ref(num).cast_mut();
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:21:16
   |
LL |     let _num = &mut *std::ptr::from_ref({ num }).cast_mut();
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:23:16
   |
LL |     let _num = &mut *{ std::ptr::from_ref(num) }.cast_mut();
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:25:16
   |
LL |     let _num = &mut *(std::ptr::from_ref({ num }) as *mut i32);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:27:16
   |
LL |     let _num = &mut *std::mem::transmute::<_, *mut i32>(num);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:31:16
   |
LL |     let deferred = num as *const i32 as *mut i32;
   |                    ----------------------------- casting happend here
LL |     let _num = &mut *deferred;
   |                ^^^^^^^^^^^^^^

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:40:5
   |
LL |     *(a as *const _ as *mut _) = String::from("Replaced");
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:42:5
   |
LL |     *(a as *const _ as *mut String) += " world";
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:44:5
   |
LL |     *std::ptr::from_ref(num).cast_mut() += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:46:5
   |
LL |     *std::ptr::from_ref({ num }).cast_mut() += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:48:5
   |
LL |     *{ std::ptr::from_ref(num) }.cast_mut() += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:50:5
   |
LL |     *(std::ptr::from_ref({ num }) as *mut i32) += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:52:5
   |
LL |     *std::mem::transmute::<_, *mut i32>(num) += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:56:5
   |
LL |     let value = num as *const i32 as *mut i32;
   |                 ----------------------------- casting happend here
LL |     *value = 1;
   |     ^^^^^^^^^^

error: aborting due to 16 previous errors