defining container with Any type, it sometime requires type cast.

container_any.kt

//any型
//どのような型でも受け取るコンテナ
class Container(var value: Any)

//どのような型でも受取、コンテナに詰める
fun packer(value: Any): Container{
    return Container(value)
}

//コンテナの中身を確認する
fun officer(containers: List<Container>){
    for(item in containers){
        println("value = ${item.value}")
    }        
}

fun main() {
    val intContainer = Container(100)
    val strContainer = Container("hello")
    
    //要キャスト
    val i: Int = intContainer.value as Int
    val s: String = strContainer.value as String
    
    println("i = ${i}")
    println("s = ${s.uppercase()}")
    
    var containers: List<Container> = emptyList()
    containers += packer(100)
    containers += packer("amazon")
    containers += packer(false)
    
    officer(containers)
}