I'm confused by a paragraph in the documentation on functional interfaces:

```fun interface Printer {

fun print()

}```

Its constructor will be created implicitly, and any code using the

::Printer

function reference will compile. For example:

documentsStorage.addPrinter(::Printer)

On this page, the

addPrinter

function is not mentioned anywhere. What would its parameter type be, and how would it be used?

probably:

fun DocumentsStorage.addPrinter(printer: (() -> Unit) -> Printer)

Not sure how useful it really is to be honest.

given that the code above it has

fun Printer(block: () -> Unit): Printer

that is the declaration

::Printer

was referencing previously, and the docs say that works with

fun interface

and no additional function instead

I see, thanks