enum.md

Enumerated types

r[type.enum]

r[type.enum.intro] An enumerated type is a nominal, heterogeneous disjoint union type, denoted by the name of an enum item. ¹

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.

Footnotes

1. The enum type is analogous to a data constructor declaration in Haskell, or a pick ADT in Limbo. ↩