rust-lang / rust-lang/rust

Constructing struct through associated type in trait fails with E0599

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A-diagnostics T-compiler
Dominant language
Rust
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Description

Code
trait T{
    type A;
    
    fn f();
}

struct S(());

impl T for (){
    type A=S;
    fn f(){
        Self::A(());
    }
}
Current output
error[E0599]: no associated item named `A` found for unit type `()` in the current scope
  --> tmp.rs:12:15
   |
12 |         Self::A(());
   |               ^ associated item not found in `()`
Desired output

No response

Rationale and extra context

I am not sure if this is just a problem with the error message being wrong, or if this should actually compile.

Other cases

No response

Rust Version
rustc 1.77.2 (25ef9e3d8 2024-04-09)
binary: rustc
commit-hash: 25ef9e3d85d934b27d9dada2f9dd52b1dc63bb04
commit-date: 2024-04-09
host: x86_64-unknown-linux-gnu
release: 1.77.2
LLVM version: 17.0.6
Anything else?

No response

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First steps

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Research direction

Start by reproducing the example in tmp.rs with rustc 1.77.2 and inspect how the compiler resolves Self::A(()). Determine whether this should compile or produce a different diagnostic; the issue is done when the expected behavior is established and the compiler handling is corrected accordingly.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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