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 *(num as *const i32 as *mut i32);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>
   = 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:21:16
   |
LL |     let _num = &mut *(num as *const i32).cast_mut();
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

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();
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

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 }).cast_mut();
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

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::ptr::from_ref(num) }.cast_mut();
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:29:16
   |
LL |     let _num = &mut *(std::ptr::from_ref({ num }) as *mut i32);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

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 _num = &mut *(num as *const i32).cast::<i32>().cast_mut();
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:33:16
   |
LL |     let _num = &mut *(num as *const i32).cast::<i32>().cast_mut().cast_const().cast_mut();
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:35:16
   |
LL |     let _num = &mut *(std::ptr::from_ref(static_u8()) as *mut i32);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:37:16
   |
LL |     let _num = &mut *std::mem::transmute::<_, *mut i32>(num);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:39:16
   |
LL |     let _num = &mut *(std::mem::transmute::<_, *mut i32>(num) as *mut i32);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:41:16
   |
LL |       let _num = &mut *std::cell::UnsafeCell::raw_get(
   |  ________________^
LL | |
LL | |         num as *const i32 as *const std::cell::UnsafeCell<i32>
LL | |     );
   | |_____^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:47:16
   |
LL |     let deferred = num as *const i32 as *mut i32;
   |                    ----------------------------- casting happend here
LL |     let _num = &mut *deferred;
   |                ^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:50:16
   |
LL |     let deferred = (std::ptr::from_ref(num) as *const i32 as *const i32).cast_mut() as *mut i32;
   |                    ---------------------------------------------------------------------------- casting happend here
LL |     let _num = &mut *deferred;
   |                ^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:53:16
   |
LL |     let deferred = (std::ptr::from_ref(num) as *const i32 as *const i32).cast_mut() as *mut i32;
   |                    ---------------------------------------------------------------------------- casting happend here
...
LL |     let _num = &mut *deferred_rebind;
   |                ^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:55:16
   |
LL |     let _num = &mut *(num as *const _ as usize as *mut i32);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:57:16
   |
LL |     let _num = &mut *(std::mem::transmute::<_, *mut _>(num as *const i32) as *mut i32);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:64:16
   |
LL |     let num = NUM as *const i32 as *mut i32;
   |               ----------------------------- casting happend here
...
LL |     let _num = &mut *num;
   |                ^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:68:16
   |
LL |     let _num = &mut *(cell as *const _ as *mut i32);
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>
   = note: even for types with interior mutability, the only legal way to obtain a mutable pointer from a shared reference is through `UnsafeCell::get`

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:72:9
   |
LL |         &mut *((this as *const _) as *mut _)
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:77:18
   |
LL |         unsafe { &mut *std::cell::UnsafeCell::raw_get(x as *const _ as *const _) }
   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
  --> $DIR/reference_casting.rs:82:18
   |
LL |         unsafe { &mut *std::cell::UnsafeCell::raw_get(x as *const _ as *const _) }
   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:92:5
   |
LL |     *(a as *const _ as *mut _) = String::from("Replaced");
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:94:5
   |
LL |     *(a as *const _ as *mut String) += " world";
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:96:5
   |
LL |     *std::ptr::from_ref(num).cast_mut() += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:98:5
   |
LL |     *std::ptr::from_ref({ num }).cast_mut() += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:100:5
   |
LL |     *{ std::ptr::from_ref(num) }.cast_mut() += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:102:5
   |
LL |     *(std::ptr::from_ref({ num }) as *mut i32) += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:104:5
   |
LL |     *std::mem::transmute::<_, *mut i32>(num) += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:106:5
   |
LL |     *(std::mem::transmute::<_, *mut i32>(num) as *mut i32) += 1;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:108:5
   |
LL | /     std::ptr::write(
LL | |
LL | |         std::mem::transmute::<*const i32, *mut i32>(num),
LL | |         -1i32,
LL | |     );
   | |_____^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:113:5
   |
LL |     *((&std::cell::UnsafeCell::new(0)) as *const _ as *mut i32) = 5;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>
   = note: even for types with interior mutability, the only legal way to obtain a mutable pointer from a shared reference is through `UnsafeCell::get`

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:117:5
   |
LL |     let value = num as *const i32 as *mut i32;
   |                 ----------------------------- casting happend here
LL |     *value = 1;
   |     ^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:120:5
   |
LL |     let value = num as *const i32 as *mut i32;
   |                 ----------------------------- casting happend here
...
LL |     *value_rebind = 1;
   |     ^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:122:5
   |
LL |     *(num as *const i32).cast::<i32>().cast_mut() = 2;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:124:5
   |
LL |     *(num as *const _ as usize as *mut i32) = 2;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:126:5
   |
LL |     let value = num as *const i32 as *mut i32;
   |                 ----------------------------- casting happend here
...
LL |     std::ptr::write(value, 2);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:128:5
   |
LL |     let value = num as *const i32 as *mut i32;
   |                 ----------------------------- casting happend here
...
LL |     std::ptr::write_unaligned(value, 2);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:130:5
   |
LL |     let value = num as *const i32 as *mut i32;
   |                 ----------------------------- casting happend here
...
LL |     std::ptr::write_volatile(value, 2);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
  --> $DIR/reference_casting.rs:134:9
   |
LL |         *(this as *const _ as *mut _) = a;
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>

error: aborting due to 40 previous errors