ices/68644.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#68644

#![feature(generic_associated_types)]

trait Fun {
    type F<'a>: Fn() -> u32;
    
    fn callme<'a>(f: Self::F<'a>) -> u32 {
        f()
    }
}

impl <T> Fun for T {
    type F<'a> = Self;
}

fn main() {
    <u8>::callme(0);
}

=== stdout ===
=== stderr ===
warning: the feature `generic_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes
 --> /home/runner/work/glacier/glacier/ices/68644.rs:1:12
  |
1 | #![feature(generic_associated_types)]
  |            ^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(incomplete_features)]` on by default
  = note: see issue #44265 <https://github.com/rust-lang/rust/issues/44265> for more information

error[E0277]: expected a `std::ops::Fn<()>` closure, found `T`
  --> /home/runner/work/glacier/glacier/ices/68644.rs:12:5
   |
4  |     type F<'a>: Fn() -> u32;
   |     ------------------------ required by `Fun::F`
...
12 |     type F<'a> = Self;
   |     ^^^^^^^^^^^^^^^^^^ expected an `Fn<()>` closure, found `T`
   |
   = help: the trait `std::ops::Fn<()>` is not implemented for `T`
   = note: wrap the `T` in a closure with no arguments: `|| { /* code */ }
help: consider restricting type parameter `T`
   |
11 | impl <T: std::ops::Fn<()>> Fun for T {
   |        ^^^^^^^^^^^^^^^^^^

error: aborting due to previous error; 1 warning emitted

For more information about this error, try `rustc --explain E0277`.
==============