/-! # Projections on types without fields https://github.com/leanprover/lean4/issues/9312 Ensures that a suitable error message is displayed when attempting to project from a type that has no fields. -/ structure MyEmpty where /-- error: Invalid projection: Projections are not supported on this type because it has no fields { } has type MyEmpty -/ #guard_msgs in #check (MyEmpty.mk).1 inductive T where | a /-- error: Invalid projection: Projections are not supported on this type because it has no fields T.a has type T -/ #guard_msgs in #check (T.a).1