rust/tests/ui/nll/unexpected-inference-var-ice-116599.rs
Matthias Krüger db68dc27f4 add test for #116599
Fixes #116599
2024-03-24 10:05:27 +01:00

45 lines
1.1 KiB
Rust

// ICE unexpected inference var
// issue: rust-lang/rust#116599
//@ check-pass
pub trait EvaluateConstMethods {
type Trait: TraitWithConstMethods;
/// **This block breaks**
const DATA_3: Data3 = {
<<<Self::Trait as TraitWithConstMethods>::Method2 as ConstFn<_, _>>::Body<
<<Self::Trait as TraitWithConstMethods>::Method1 as ConstFn<_, _>>::Body<ContainsData1>,
> as Contains<_>>::ITEM
};
}
pub trait TraitWithConstMethods {
/// "const trait method" of signature `fn(Data1) -> Data2`
type Method1: ConstFn<Data1, Data2>;
/// "const trait method" of signature `fn(Data2) -> Data3`
type Method2: ConstFn<Data2, Data3>;
}
/// A trait which tries to implement const methods in traits
pub trait ConstFn<Arg, Ret> {
type Body<T: Contains<Arg>>: Contains<Ret>;
}
/// A ZST which represents / "contains" a const value which can be pass to a [`ConstFn`]
pub trait Contains<T> {
const ITEM: T;
}
pub struct ContainsData1;
impl Contains<Data1> for ContainsData1 {
const ITEM: Data1 = Data1 {};
}
// Arbitrary data
pub struct Data1 {}
pub struct Data2 {}
pub struct Data3 {}
pub fn main() {}