Enums

Map integer values to a fixed set with c.enum(storage, map):

const Status = {
  Ok: 0,
  Error: 1,
} as const;

@c.struct()
class Packet {
  @c.field(c.enum("u8", Status))
  status!: number;
}

Values are validated on read and write. Use pad_after on the same field when the layout has trailing padding after a small enum storage type.

C equivalent — integer storage with a fixed set of named constants:

typedef enum {
    Status_Ok = 0,
    Status_Error = 1,
} Status;

typedef struct {
    uint8_t status; /* c.enum("u8", Status) */
} Packet;

You can also write the slot as a plain integer and compare against macros:

#define STATUS_OK    0
#define STATUS_ERROR 1

typedef struct {
    uint8_t status;
} Packet;

cstruct’s c.enum() is the typed version of that pattern: it checks the value is one of the allowed constants on read and write. The storage type (u8, u16, …) is the width of the integer field in the struct.

For combinable flag bits in one integer, see Bitfield.

Enums ​

Enums