A function reference passed as an argument to an inline function will not be inlined. Is that corre...

# getting-started

[julian]

A function reference passed as an argument to an inline function will not be inlined. Is that correct?
That's what it looks like from the bytecode, but I'm on shaky ground when making sense of bytecode.

[ephemient]

can you provide an example of what you mean?

[ephemient]

these are both inlined:

Unit.let(::println)
Unit.let { println(it) }

[Dominaezzz]

The contents of println are inlined?!

[ephemient]

not the contents of println, but there is no wrapper object constructed

[ephemient]

e.g. different from val f: (Any) -> Unit = ::println / val f = { println(it) }

[Dominaezzz]

Ah of course.

[Dominaezzz]

I understand the question to be, "will the contents of println be inlined?"

[julian]

Yup @Dominaezzz. That's what I intended to ask, but wasn't clear.

[julian]

Thanks @ephemient. println will not be inlined. Just the call to println is inlined.

[julian]

Haha! Actually, println is an inline function itself, so its content will be inlined. But, if it wasn't an inline function, its content wouldn't be inlined, even when passed as an argument (by function reference) to an inline function. Phew! 😅

[Stephan Schroeder]

also check up on noinline and crossinline : https://kotlinlang.org/docs/inline-functions.html