error[E0121]: the placeholder `_` is not allowed within types on item signatures for closures
  --> $DIR/missing-body.rs:5:23
   |
LL | fn main() { |b: [str; _]| {}; }
   |                       ^ not allowed in type signatures

error[E0277]: the size for values of type `str` cannot be known at compilation time
  --> $DIR/missing-body.rs:5:17
   |
LL | fn main() { |b: [str; _]| {}; }
   |                 ^^^^^^^^ doesn't have a size known at compile-time
   |
   = help: the trait `Sized` is not implemented for `str`
   = note: slice and array elements must have `Sized` type

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0121, E0277.
For more information about an error, try `rustc --explain E0121`.