fun Int.format(format: String): String {
    return String.format(format, this)
}

generateSequence(x) { it }

Vec3t<Number>

Float

Int

dot(v: Vec3t<Number>)

dot(v: Vec3t<Float>)

val vert = Vec3() // Vert3 : Vec3t<Float>
vert.dot(fromTo) // error, none of the following functions can be called. Note that dot is dot(v: Vec3t<Number>)

dot

dot(v: Vec3t<Float>)

Vec3tNumber

Vec3tFloat

Vec3t<out Number>

$ -> $

open class Human() 
class Men:Human()
class Women:Human()
val humanNation = asList(Women(), Man())

val womenForMe = humanNation.firstOrNull{ it is Women} as Women?

inline fun <reified K:T, T> List<T>.firstOrNull(): K? = firstOrNull { it is K} as K?

val womenForMe : Women = humanNation.firstOrNull()

humanNation.firstOrNull {...}

l

f

?