Kotlin: is it possible to have a constant property dependent on an implementation generic type? -


i have following abstrac base class

abstract class vec2t<t : number>(open var x: t, open var y: t) {      companion object {         val size = 2 * when (/** t instance type */) {             byte, ubyte -> 1             short, ushort -> 2             int, uint, float -> 4             long, ulong, double -> 8             else -> throw arithmeticexception("type undefined")         }     } }

that implemented, example, vec2

data class vec2(override var x: float, override var y: float) : vec2t<float>(x, y)

i wondering if possible define size in vec2t , call on 1 of implementation, example vec2.size

although cannot "have static fields have different values different instantiations of generic class" (as @yole commented), can define properties on each implementation , companion objects. e.g.:

abstract class vec2t<t : number> {     abstract var x: t     abstract var y: t     abstract val size: int }  class vec2f(override var x: float, override var y: float) : vec2t<float>() {     companion object {         const val size = 2 * 4     }      override val size: int         get() = size }  class vec2d(override var x: double, override var y: double) : vec2t<double>() {     companion object {         const val size = 2 * 8     }      override val size: int         get() = size }

this allows reference vec2f.size, vec2d.size, etc. when want know size specific implementation , reference vec2t.size when have instance (possibly of unknown implementation type) , size.


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