1 error[E0308]: mismatched types
2 --> $DIR/region-lifetime-bounds-on-fns-where-clause.rs:20:43
4 LL | let _: fn(&mut &isize, &mut &isize) = a;
5 | ^ one type is more general than the other
7 = note: expected fn pointer `for<'a, 'b, 'c, 'd> fn(&'a mut &'b isize, &'c mut &'d isize)`
8 found fn item `for<'a, 'b> fn(&'a mut &isize, &'b mut &isize) {a::<'_, '_>}`
10 error: aborting due to previous error
12 For more information about this error, try `rustc --explain E0308`.