Is there a built in Kotlin method to apply void function to value?

Question

I wrote this method to apply a void function to a value and return the value.

public inline fun  T.apply(f: (T) -> Unit): T {
    f(this)
    ret         


        

Answer 1

I ran into the same problem. My solution is basicly the same as yours with a small refinement:

inline fun  T.apply(f: T.() -> Any): T {
    this.f()
    return this
}

Note, that f is an extension function. This way you can invoke methods on your object using the implicit this reference. Here's an example taken from a libGDX project of mine:

val sprite : Sprite = atlas.createSprite("foo") apply {
    setSize(SIZE, SIZE)
    setOrigin(SIZE / 2, SIZE / 2)
}

Of course you could also call doStuff(this).