let mut err = struct_span_err!(tcx.sess, sp, E0731, "transparent enum {}", msg);
err.span_label(sp, &msg);
if let [start @ .., end] = &*variant_spans {
let mut err = struct_span_err!(tcx.sess, sp, E0731, "transparent enum {}", msg);
err.span_label(sp, &msg);
if let [start @ .., end] = &*variant_spans {