error[E0282]: type annotations needed for `[usize; _]`
  --> $DIR/issue-83606.rs:8:9
   |
LL |     let _ = foo("foo");
   |         ^
   |
help: consider giving this pattern a type, where the value of const parameter `N` is specified
   |
LL |     let _: [usize; N] = foo("foo");
   |          ++++++++++++

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0282`.