error[E0769]: tuple variant `S` written as struct variant
  --> $DIR/missing-fields-in-struct-pattern.rs:4:12
   |
LL |     if let S { a, b, c, d } = S(1, 2, 3, 4) {
   |            ^^^^^^^^^^^^^^^^ help: use the tuple variant pattern syntax instead: `S(a, b, c, d)`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0769`.