在 VK 中, 有如下四种声明和类型的方式

Keywords	Layout	Detail
enumerate	[u8; N]	A number, used to represent different states
flags	[u8; N]	A number used to represent different binary opposite states
union	[u8; X]	Some bytes, used to represent different states
unite	[u8; N][u8; X]	Some bytes, used to represent different states

• X is the largest size of all variant types
• N is the given size of the representation