error[E0609]: no field `1` on type `Foo`
  --> $DIR/ex-E0612.rs:5:6
   |
LL |    y.1;
   |      ^ unknown field
   |
help: a field with a similar name exists
   |
LL |    y.0;
   |      ~

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0609`.