error: ~const can only be applied to `#[const_trait]` traits
  --> $DIR/const_trait_impl.rs:34:16
   |
LL | impl<T: ~const Default> const A for T {
   |                ^^^^^^^

error: ~const can only be applied to `#[const_trait]` traits
  --> $DIR/const_trait_impl.rs:40:16
   |
LL | impl<T: ~const Default + ~const Sup> const A for T {
   |                ^^^^^^^

error: ~const can only be applied to `#[const_trait]` traits
  --> $DIR/const_trait_impl.rs:46:16
   |
LL | impl<T: ~const Default + ~const Sub> const A for T {
   |                ^^^^^^^

error: aborting due to 3 previous errors