error[E0658]: custom discriminant values are not allowed in enums with tuple or struct variants
  --> $DIR/issue-17383.rs:2:9
   |
LL |     A = 3,
   |         ^ disallowed custom discriminant
LL |
LL |     B(usize)
   |     -------- tuple variant defined here
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/60553
   = help: add `#![feature(arbitrary_enum_discriminant)]` to the crate attributes to enable

error: aborting due to previous error

For more information about this error, try `rustc --explain E0658`.