error[E0277]: the trait bound `T: ~const Sup` is not satisfied
  --> $DIR/specializing-constness-2.rs:27:5
   |
LL |     <T as A>::a();
   |     ^^^^^^^^^^^^^ the trait `~const Sup` is not implemented for `T`
   |
note: required for `T` to implement `~const A`
  --> $DIR/specializing-constness-2.rs:20:37
   |
LL | impl<T: Default + ~const Sup> const A for T {
   |                   ----------        ^     ^
   |                   |
   |                   unsatisfied trait bound introduced here
help: consider further restricting this bound
   |
LL | const fn generic<T: Default + ~const Sup>() {
   |                             ++++++++++++

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.