With the data type, you get the destruction out of the box. But, can we achieve the same thing without a data class? The answer is yes. All you have to do is provide the componentN methods. The only requirement is to prefix each method definition with the keyword operator. Let's say we have a class Vector3
that represents the coordinates in a 3D space. For the sake of an argument, we will not make this class a data class:
class Vector3(val x:Double, val y:Double, val z:Double){ operator fun component1()=x operator fun component2()=y operator funcomponent3()=z } for ((x,y,z) in listOf(Vector3(0.2,0.1,0.5), Vector3(-12.0, 3.145, 5.100))){ println("Coordinates: x=$x, y=$y, z=$z") }
As you can see, for each member field, we created the equivalent componentN method. Because of this, the compiler can apply the destruction during a for
loop construct.
What if you are dealing with a library...