Inherent associated type projections are not normalized after substitution #105314
Description
I tried this code:
#![feature(inherent_associated_types)] #![allow(incomplete_features)] struct S<T>(T); impl<T: O> S<T> { type P = <T as O>::P; } trait O { type P; } impl O for i32 { type P = String; } fn main() { let _: S<i32>::P = String::new(); }I expected to see it compile successfully.
Instead, it was rejected with the following error message:
error[E0308]: mismatched types --> p0.rs:15:24 | 15 | let _: S<i32>::P = String::new(); | --------- ^^^^^^^^^^^^^ expected associated type, found struct `String` | | | expected due to this | = note: expected associated type `<i32 as O>::P` found struct `String` = help: consider constraining the associated type `<i32 as O>::P` to `String` or calling a method that returns `<i32 as O>::P` = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html help: call `Into::into` on this expression to convert `String` into `<i32 as O>::P` | 15 | let _: S<i32>::P = String::new().into(); | +++++++ Meta
rustc -Vv:
rustc 1.67.0-nightly (53e4b9dd7 2022-12-04) binary: rustc commit-hash: 53e4b9dd74c29cc9308b8d0f10facac70bb101a7 commit-date: 2022-12-04 host: x86_64-unknown-linux-gnu release: 1.67.0-nightly LLVM version: 15.0.4