rustc-ap-rustc_error_codes 638.0.0

Automatically published version of the package `rustc_error_codes` in the rust-lang/rust repository from commit 30ca215b4e38b32aa7abdd635c5e2d56f5724494 The publishing script for this crate lives at: https://github.com/alexcrichton/rustc-auto-publish
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21

`impl Trait` types cannot appear nested in the
generic arguments of other `impl Trait` types.

Example of erroneous code:

```compile_fail,E0666
trait MyGenericTrait<T> {}
trait MyInnerTrait {}

fn foo(bar: impl MyGenericTrait<impl MyInnerTrait>) {}
```

Type parameters for `impl Trait` types must be
explicitly defined as named generic parameters:

```
trait MyGenericTrait<T> {}
trait MyInnerTrait {}

fn foo<T: MyInnerTrait>(bar: impl MyGenericTrait<T>) {}
```