Compiler error with member parametrized by const generic

[imbrem]

When you parameterize struct members by const generics you get the same sort of errors as when parametrizing impls by const generics (#60800)

#![feature(const_generics)]

struct Member<const N : usize>();

#[allow(dead_code)]
struct Foo<const N : usize> {
    member : Member<N>
}

(Playground)

Errors:

   Compiling playground v0.0.1 (/playground)
warning: the feature `const_generics` is incomplete and may cause the compiler to crash
 --> src/lib.rs:1:12
  |
1 | #![feature(const_generics)]
  |            ^^^^^^^^^^^^^^

error[E0465]: multiple rlib candidates for `debug_unreachable` found
  |
  = note: candidate #1: /playground/target/debug/deps/libdebug_unreachable-b6bbaea13290bfa4.rlib
  = note: candidate #2: /playground/target/debug/deps/libdebug_unreachable-597d184d1c38b826.rlib

error[E0573]: expected type, found const parameter `N`
 --> src/lib.rs:7:21
  |
7 |     member : Member<N>
  |                     ^ not a type

error[E0107]: wrong number of const arguments: expected 1, found 0
 --> src/lib.rs:7:14
  |
7 |     member : Member<N>
  |              ^^^^^^^^^ expected 1 const argument

error[E0107]: wrong number of type arguments: expected 0, found 1
 --> src/lib.rs:7:21
  |
7 |     member : Member<N>
  |                     ^ unexpected type argument

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0107`.
error: Could not compile `playground`.

To learn more, run the command again with --verbose.

[varkor]

At the moment, you need to surround const generic arguments in curly brackets: e.g.{N}, because they can't be disambiguated from type parameters yet.

[varkor]

I've just created a catch-all issue for this: #60804. Thanks for reporting!