Thanks! I tried this myself, but I got stuck, so this will definitely help
understanding macros :D
Though, I think I will use this solution, as I will need the `func typeId[T]()`
anyway. I am not sure if it is all sound, but it at least seems to work. And
while it pretty inelegantly does all the stuff at runtime, it doesn't require
registering component types:
func getUniqueId(): int =
{.cast(noSideEffect).}:
var idCounter {.global.} = 0
result = idCounter
idCounter += 1
func typeId[T](): int =
{.cast(noSideEffect).}:
let id {.global.} = getUniqueId()
return id
type ComponentVectors = seq[ref seq[int8]]
func get[T](componentVectors: var ComponentVectors): var seq[T] =
static: doAssert (ref seq[int8]).default == nil
let id = typeId[T]()
if componentVectors.len <= id:
componentVectors.setLen(id + 1)
if componentVectors[id] == nil:
componentVectors[id] = new seq[int8]
assert componentVectors[id] != nil
cast[ref seq[T]](componentVectors[id])[]
func get[T](componentVectors: ComponentVectors): seq[T] =
let id = typeId[T]()
if componentVectors.len > id and componentVectors[id] != nil:
return cast[ref seq[T]](componentVectors[id])[]
var c: ComponentVectors
c.get[:float]().add(0.5)
c.get[:int]().add(1234)
c.get[:float]().add(0.6)
echo c.get[:float]()
echo c.get[:int]()
Run
