warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
  --> $DIR/equality2.rs:1:12
   |
LL | #![feature(specialization)]
   |            ^^^^^^^^^^^^^^
   |
   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
   = help: consider using `min_specialization` instead, which is more stable and complete
   = note: `#[warn(incomplete_features)]` on by default

error[E0308]: mismatched types
  --> $DIR/equality2.rs:25:18
   |
LL | fn hide<T: Foo>(x: T) -> impl Foo {
   |                          -------- the found opaque type
...
LL |     let _: u32 = hide(0_u32);
   |            ---   ^^^^^^^^^^^ expected `u32`, found opaque type
   |            |
   |            expected due to this
   |
   = note:     expected type `u32`
           found opaque type `impl Foo`

error[E0308]: mismatched types
  --> $DIR/equality2.rs:31:18
   |
LL | fn hide<T: Foo>(x: T) -> impl Foo {
   |                          -------- the found opaque type
...
LL |     let _: i32 = Leak::leak(hide(0_i32));
   |            ---   ^^^^^^^^^^^^^^^^^^^^^^^ expected `i32`, found associated type
   |            |
   |            expected due to this
   |
   = note:         expected type `i32`
           found associated type `<impl Foo as Leak>::T`
help: consider constraining the associated type `<impl Foo as Leak>::T` to `i32`
   |
LL | fn hide<T: Foo>(x: T) -> impl Foo<T = i32> {
   |                                  +++++++++

error[E0308]: mismatched types
  --> $DIR/equality2.rs:38:10
   |
LL | fn hide<T: Foo>(x: T) -> impl Foo {
   |                          --------
   |                          |
   |                          the expected opaque type
   |                          the found opaque type
...
LL |     x = (x.1,
   |          ^^^ expected `u32`, found `i32`
   |
   = note: expected opaque type `impl Foo` (`u32`)
              found opaque type `impl Foo` (`i32`)

error[E0308]: mismatched types
  --> $DIR/equality2.rs:41:10
   |
LL | fn hide<T: Foo>(x: T) -> impl Foo {
   |                          --------
   |                          |
   |                          the expected opaque type
   |                          the found opaque type
...
LL |          x.0);
   |          ^^^ expected `i32`, found `u32`
   |
   = note: expected opaque type `impl Foo` (`i32`)
              found opaque type `impl Foo` (`u32`)

error: aborting due to 4 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0308`.