math - Kotlin, generic addition -

is possible implement generic, let's say, addition following:

public abstract interface numberex {      abstract fun plus(other: numberex): numberex }  abstract interface vec2t<t : numberex> {      open var x: t     open var y: t      fun add(res: vec2t<t>, a: vec2t<t>, bx: t, by: t): vec2t<t> {         res.x = a.x + bx         res.y = a.y +         return res     } } 

because here compilers complains a.x + bx , a.y + by:

type mismatch. required: t found: numberex

one way employ recursive numberex definition so:

interface numberex<t : numberex<t>> {     operator fun plus(other: t): t } 

this require implementation provide plus operator:

class anumber : numberex<anumber> {     override fun plus(other: anumber): anumber {         //todo     } } 

and make type safe , understandable compiler use in vec2t

interface vec2t<t : numberex<t>> {   ... }