warning: trait objects without an explicit `dyn` are deprecated
  --> $DIR/unspecified-self-in-trait-ref.rs:10:13
   |
LL |     let a = Foo::lol();
   |             ^^^
   |
   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
   = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
   = note: `#[warn(bare_trait_objects)]` on by default
help: if this is an object-safe trait, use `dyn`
   |
LL |     let a = <dyn Foo>::lol();
   |             ++++    +

error[E0599]: no function or associated item named `lol` found for trait object `dyn Foo<_>` in the current scope
  --> $DIR/unspecified-self-in-trait-ref.rs:10:18
   |
LL |     let a = Foo::lol();
   |                  ^^^ function or associated item not found in `dyn Foo<_>`

warning: trait objects without an explicit `dyn` are deprecated
  --> $DIR/unspecified-self-in-trait-ref.rs:14:13
   |
LL |     let b = Foo::<_>::lol();
   |             ^^^^^^^^
   |
   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
   = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
help: if this is an object-safe trait, use `dyn`
   |
LL |     let b = <dyn Foo::<_>>::lol();
   |             ++++         +

error[E0599]: no function or associated item named `lol` found for trait object `dyn Foo<_>` in the current scope
  --> $DIR/unspecified-self-in-trait-ref.rs:14:23
   |
LL |     let b = Foo::<_>::lol();
   |                       ^^^ function or associated item not found in `dyn Foo<_>`

warning: trait objects without an explicit `dyn` are deprecated
  --> $DIR/unspecified-self-in-trait-ref.rs:18:13
   |
LL |     let c = Bar::lol();
   |             ^^^
   |
   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
   = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
help: if this is an object-safe trait, use `dyn`
   |
LL |     let c = <dyn Bar>::lol();
   |             ++++    +

error[E0599]: no function or associated item named `lol` found for trait object `dyn Bar<_, _>` in the current scope
  --> $DIR/unspecified-self-in-trait-ref.rs:18:18
   |
LL |     let c = Bar::lol();
   |                  ^^^ function or associated item not found in `dyn Bar<_, _>`

warning: trait objects without an explicit `dyn` are deprecated
  --> $DIR/unspecified-self-in-trait-ref.rs:22:13
   |
LL |     let d = Bar::<usize, _>::lol();
   |             ^^^^^^^^^^^^^^^
   |
   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
   = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
help: if this is an object-safe trait, use `dyn`
   |
LL |     let d = <dyn Bar::<usize, _>>::lol();
   |             ++++                +

error[E0599]: no function or associated item named `lol` found for trait object `dyn Bar<usize, _>` in the current scope
  --> $DIR/unspecified-self-in-trait-ref.rs:22:30
   |
LL |     let d = Bar::<usize, _>::lol();
   |                              ^^^ function or associated item not found in `dyn Bar<usize, _>`

warning: trait objects without an explicit `dyn` are deprecated
  --> $DIR/unspecified-self-in-trait-ref.rs:26:13
   |
LL |     let e = Bar::<usize>::lol();
   |             ^^^^^^^^^^^^
   |
   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
   = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
help: if this is an object-safe trait, use `dyn`
   |
LL |     let e = <dyn Bar::<usize>>::lol();
   |             ++++             +

error[E0393]: the type parameter `A` must be explicitly specified
  --> $DIR/unspecified-self-in-trait-ref.rs:26:13
   |
LL | pub trait Bar<X=usize, A=Self> {
   | ------------------------------ type parameter `A` must be specified for this
...
LL |     let e = Bar::<usize>::lol();
   |             ^^^^^^^^^^^^ missing reference to `A`
   |
   = note: because of the default `Self` reference, type parameters must be specified on object types

error: aborting due to 5 previous errors; 5 warnings emitted

Some errors have detailed explanations: E0393, E0599.
For more information about an error, try `rustc --explain E0393`.