| r[type.enum] | |
| # Enumerated types | |
| r[type.enum.intro] | |
| An *enumerated type* is a nominal, heterogeneous disjoint union type, denoted by the name of an [`enum` item]. [^enumtype] | |
| r[type.enum.declaration] | |
| An [`enum` item] declares both the type and a number of *variants*, each of which is independently named and has the syntax of a struct, tuple struct or unit-like struct. | |
| r[type.enum.constructor] | |
| New instances of an `enum` can be constructed with a [struct expression]. | |
| r[type.enum.value] | |
| Any `enum` value consumes as much memory as the largest variant for its corresponding `enum` type, as well as the size needed to store a discriminant. | |
| r[type.enum.name] | |
| Enum types cannot be denoted *structurally* as types, but must be denoted by named reference to an [`enum` item]. | |
| [^enumtype]: The `enum` type is analogous to a `data` constructor declaration in Haskell, or a *pick ADT* in Limbo. | |
| [`enum` item]: ../items/enumerations.md | |
| [struct expression]: ../expressions/struct-expr.md |