FunctionReferences4.kt

fun main() {
    val classOne = ClassOne()
    
    val color1 = classOne.obtainColor(context, R.color.my_color)
    
    val classTwo = ClassTwo()
    
    classTwo.obtainColor(R.color.my_color, context.resources::getColor)
}

class ClassOne() {
    
    fun obtainColor(context: Context, colorRes: Int) = context.resources.getColor(colorRes)
}

class ClassTwo {
    fun obtainColor(colorRes: Int, colorLookup: (Int) -> Int) = colorLookup(colorRes)
}