Best way to handle such scenario where “smart cast is imposible”

Question

I wonder what is the best way to handle such scenario

class Person(var name:String? = null, var age:Int? = null){
    fun test(){
        if(name != null &am         


        

Answer 1

In addition to miensol's answer there are various ways to copy property values into function variables to enable smart cast. e.g.:

1. Intermediary function:

   class Person(var name: String? = null, var age: Int? = null) {
       fun test() = test(name, age)
       private fun test(name: String?, age: Int?) {
           if (name != null && age != null)
               doSth(name, age) //smart cast possible
       }
   
       fun doSth(someValue: String, someValue2: Int) {
   
       }
   }
   

2. Anonymous function:

   class Person(var name: String? = null, var age: Int? = null) {
       fun test() = (fun(name: String?, age: Int?) {
           if (name != null && age != null)
               doSth(name, age) //smart cast possible
       })(name, age)
   
       fun doSth(someValue: String, someValue2: Int) {
   
       }
   }
   

3. Default arguments:

   class Person(var name: String? = null, var age: Int? = null) {
       fun test(name: String? = this.name, age: Int? = this.age) {
           if (name != null && age != null)
               doSth(name, age) //smart cast possible
       }
   
       fun doSth(someValue: String, someValue2: Int) {
   
       }
   }