error: borrowed data escapes outside of function
  --> $DIR/issue-50716.rs:25:14
   |
LL | fn foo<'a, T: 'static>(s: Box<<&'a T as A>::X>)
   |                        - `s` is a reference that is only valid in the function body
...
LL |     let _x = *s; //~ ERROR
   |              ^^ `s` escapes the function body here

error: aborting due to previous error