{"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"//!"}]}
//! type `Option<!>`. What this all means is that `ConstructorSet` must know which constructors are
//! Let's call "empty" a constructor that matches no valid value for the type, like `Some` for the
//! empty. The difference between empty and nonempty constructors is that empty constructors need