ices/104196.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#104196

use core::future::Future;

pub struct Struct<C, Fu, F>
where
    F: Fn(&C) -> Fu,
    Fu: Future,
{
    handler: F,
    context: C,
}

impl<C, Fu, R, F> Struct<C, Fu, F>
where
    F: Fn(&C) -> Fu,
    Fu: Future<Output = R>,
{
    pub const fn new(handler: F, context: C) -> Self {
        Self { handler, context }
    }
}

type TestC = &'static usize;
type TestFu = impl Future;
type TestF = impl Fn(&TestC) -> TestFu;
type TestStruct = Struct<TestC, TestFu, TestF>;

async fn test_handler(context: &TestC) -> () {
    ()
}

fn get_test_struct() -> &'static TestStruct {
    static test_actor: TestStruct = TestStruct::new(test_handler, &0);
    &test_actor
}

fn main() {}

=== stdout ===
=== stderr ===
error[E0658]: `impl Trait` in type aliases is unstable
  --> /home/runner/work/glacier/glacier/ices/104196.rs:23:15
   |
23 | type TestFu = impl Future;
   |               ^^^^^^^^^^^
   |
   = note: see issue #63063 <https://github.com/rust-lang/rust/issues/63063> for more information
   = help: add `#![feature(type_alias_impl_trait)]` to the crate attributes to enable

error[E0658]: `impl Trait` in type aliases is unstable
  --> /home/runner/work/glacier/glacier/ices/104196.rs:24:14
   |
24 | type TestF = impl Fn(&TestC) -> TestFu;
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #63063 <https://github.com/rust-lang/rust/issues/63063> for more information
   = help: add `#![feature(type_alias_impl_trait)]` to the crate attributes to enable

error[E0391]: cycle detected when computing type of `TestF::{opaque#0}`
  --> /home/runner/work/glacier/glacier/ices/104196.rs:24:14
   |
24 | type TestF = impl Fn(&TestC) -> TestFu;
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^
   |
note: ...which requires borrow-checking `get_test_struct::test_actor`...
  --> /home/runner/work/glacier/glacier/ices/104196.rs:32:5
   |
32 |     static test_actor: TestStruct = TestStruct::new(test_handler, &0);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires promoting constants in MIR for `get_test_struct::test_actor`...
  --> /home/runner/work/glacier/glacier/ices/104196.rs:32:5
   |
32 |     static test_actor: TestStruct = TestStruct::new(test_handler, &0);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires const checking `get_test_struct::test_actor`...
  --> /home/runner/work/glacier/glacier/ices/104196.rs:32:5
   |
32 |     static test_actor: TestStruct = TestStruct::new(test_handler, &0);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = note: ...which requires computing whether `Struct<&usize, TestFu, TestF>` is freeze...
   = note: ...which requires evaluating trait selection obligation `Struct<&usize, TestFu, TestF>: core::marker::Freeze`...
   = note: ...which again requires computing type of `TestF::{opaque#0}`, completing the cycle
   = note: cycle used when evaluating trait selection obligation `Struct<&'static usize, TestFu, TestF>: core::marker::Sync`
   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information

error[E0700]: hidden type for `TestFu` captures lifetime that does not appear in bounds
  --> /home/runner/work/glacier/glacier/ices/104196.rs:32:37
   |
23 | type TestFu = impl Future;
   |               ----------- opaque type defined here
24 | type TestF = impl Fn(&TestC) -> TestFu;
   |                      - hidden type `impl for<'a> Future<Output = ()>` captures the lifetime `'_` as defined here
...
32 |     static test_actor: TestStruct = TestStruct::new(test_handler, &0);
   |                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: cannot check whether the hidden type of `104196[f0d6]::TestF::{opaque#0}` satisfies auto traits
  --> /home/runner/work/glacier/glacier/ices/104196.rs:32:24
   |
32 |     static test_actor: TestStruct = TestStruct::new(test_handler, &0);
   |                        ^^^^^^^^^^
   |
note: opaque type is declared here
  --> /home/runner/work/glacier/glacier/ices/104196.rs:24:14
   |
24 | type TestF = impl Fn(&TestC) -> TestFu;
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^
note: required because it appears within the type `Struct<&usize, TestFu, TestF>`
  --> /home/runner/work/glacier/glacier/ices/104196.rs:3:12
   |
3  | pub struct Struct<C, Fu, F>
   |            ^^^^^^
   = note: shared static variables must have a type that implements `Sync`

error: aborting due to 5 previous errors

Some errors have detailed explanations: E0391, E0658, E0700.
For more information about an error, try `rustc --explain E0391`.
==============