Unions

Just like structs, unions support embedding.

  1. struct Rgba32_Component {
  2.     r byte
  3.     g byte
  4.     b byte
  5.     a byte
  6. }
  8. union Rgba32 {
  9.     Rgba32_Component
  10.     value u32
  11. }
  13. clr1 := Rgba32{
  14.     value: 0x008811FF
  15. }
  17. clr2 := Rgba32{
  18.     Rgba32_Component: Rgba32_Component{
  19.         a: 128
  20.     }
  21. }
  23. sz := sizeof(Rgba32)
  24. unsafe {
  25.     println('Size: ${sz}B,clr1.b: $clr1.b,clr2.b: $clr2.b')
  26. }

Output: Size: 4B, clr1.b: 136, clr2.b: 0

Union member access must be performed in an unsafe block.

Note that the embedded struct arguments are not necessarily stored in the order listed.