RA not resolving type that depends on the value of a const expr.

[Olle-Lukowski]

rust-analyzer version: rust-analyzer 1.79.0 (129f3b99 2024-06-10)

rustc version: rustc 1.79.0 (129f3b996 2024-06-10)

editor or extension: NeoVim with LSP, RustRover, and VSCode all have the same issue.

More Info: RA seems to 'know' what the type is, but just doesn't display it. Because when I explicitly set the type of the variable to the wrong option (see example), it complains...

code snippet to reproduce:

pub trait Conditional<const CONDITION: bool> {
    type Type;
}

impl<T, F> Conditional<true> for (T, F) {
    type Type = T;
}

impl<T, F> Conditional<false> for (T, F) {
    type Type = F;
}

pub type If<const C: bool, T, F> = <(T, F) as Conditional<C>>::Type;

struct Foo;

#[derive(Default)]
struct Bar;

#[derive(Default)]
struct Baz;

trait Trait {
    type Out;
    fn foo() -> Self::Out;
}

impl Trait for Foo {
    type Out = If<
        {1 < 0},
        Bar,
        Baz
    >;
    fn foo() -> Self::Out {
        Default::default()
    }
}

fn main() {
    let _foo = Foo::foo(); // Unknown, according to RA, but rustc knows whats up.
    let _foo: Bar = Foo::foo(); // Both rustc and RA error here: "mismatched types"
}