error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in type
  --> $DIR/issue-58956.rs:7:11
   |
LL | const _A: impl Lam = {
   |           ^^^^^^^^

error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in variable binding
  --> $DIR/issue-58956.rs:9:17
   |
LL |     let x: Wrap<impl Lam> = Wrap(B);
   |                 ^^^^^^^^

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0562`.