error[E0308]: mismatched types --> $DIR/dst-bad-coerce2.rs:15:33 | LL | let f3: &mut Fat<[isize]> = f2; | ----------------- ^^ types differ in mutability | | | expected due to this | = note: expected mutable reference `&mut Fat<[isize]>` found reference `&Fat<[isize; 3]>` error[E0308]: mismatched types --> $DIR/dst-bad-coerce2.rs:20:33 | LL | let f3: &mut Fat = f2; | ----------------- ^^ types differ in mutability | | | expected due to this | = note: expected mutable reference `&mut Fat` found reference `&Fat` error[E0308]: mismatched types --> $DIR/dst-bad-coerce2.rs:25:31 | LL | let f3: &mut ([isize],) = f2; | --------------- ^^ types differ in mutability | | | expected due to this | = note: expected mutable reference `&mut ([isize],)` found reference `&([isize; 3],)` error[E0308]: mismatched types --> $DIR/dst-bad-coerce2.rs:30:31 | LL | let f3: &mut (dyn Bar,) = f2; | --------------- ^^ types differ in mutability | | | expected due to this | = note: expected mutable reference `&mut (dyn Bar,)` found reference `&(Foo,)` error: aborting due to 4 previous errors For more information about this error, try `rustc --explain E0308`.