error[E0005]: refutable pattern in local binding: `_` not covered
  --> $DIR/const-match-check.rs:41:24
   |
LL |     let x: [i32; { let 0 = 0; 0 }] = [];
   |                        ^ pattern `_` not covered

error: aborting due to previous error

For more information about this error, try `rustc --explain E0005`.