error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/normalize-tait-in-const.rs:27:35
   |
LL | const fn with_positive<F: for<'a> ~const Fn(&'a Alias<'a>) + ~const Destruct>(fun: F) {
   |                                   ^^^^^^ can't be applied to `Fn`
   |
note: `Fn` can't be used with `~const` because it isn't annotated with `#[const_trait]`
  --> $SRC_DIR/core/src/ops/function.rs:LL:COL

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/normalize-tait-in-const.rs:27:35
   |
LL | const fn with_positive<F: for<'a> ~const Fn(&'a Alias<'a>) + ~const Destruct>(fun: F) {
   |                                   ^^^^^^ can't be applied to `Fn`
   |
note: `Fn` can't be used with `~const` because it isn't annotated with `#[const_trait]`
  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: unconstrained opaque type
  --> $DIR/normalize-tait-in-const.rs:14:26
   |
LL |     pub type Alias<'a> = impl T<Item = &'a ()>;
   |                          ^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `Alias` must be used in combination with a concrete type within the same crate

error[E0015]: cannot call non-const closure in constant functions
  --> $DIR/normalize-tait-in-const.rs:28:5
   |
LL |     fun(filter_positive());
   |     ^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants

error[E0308]: mismatched types
  --> $DIR/normalize-tait-in-const.rs:22:9
   |
LL |     pub type Alias<'a> = impl T<Item = &'a ()>;
   |                          --------------------- the expected opaque type
...
LL |     pub const fn filter_positive<'a>() -> &'a Alias<'a> {
   |                                           ------------- expected `&'a foo::Alias<'a>` because of return type
LL |         &&S
   |         ^^^ expected `&Alias<'_>`, found `&&S`
   |
   = note: expected reference `&'a foo::Alias<'a>`
              found reference `&&S`
note: this item must have a `#[define_opaque(foo::Alias)]` attribute to be able to define hidden types
  --> $DIR/normalize-tait-in-const.rs:21:18
   |
LL |     pub const fn filter_positive<'a>() -> &'a Alias<'a> {
   |                  ^^^^^^^^^^^^^^^

error: aborting due to 5 previous errors

Some errors have detailed explanations: E0015, E0308.
For more information about an error, try `rustc --explain E0015`.