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kotlinlang

as well as
```IconButton(onClick = scaffoldStateClick())```
gives me:
`The feature "unit conversion" is disabled`

am a bit clueless on how to fix both...

I can't see your definition of `scaffoldStateClick()`, but two questions:
(1) the `onClick` parameter expects a lambda/function, but you are INVOKING `scaffoldStateClick()`, not passing it as a parameter.  Did you mean `::scaffoldStateClick` or `scaffoldStateClick` ?
(2) If you did intend to invoke `scaffoldStateClick()` and it returns a lambda, are you sure the returned lambda is of type `()-&gt;Unit` ?

```fun scaffoldStateClick() = {
    val adScaffoldState = ADState.ADScaffoldState
    if (adScaffoldState.drawerState().isClosed) {
        adScaffoldState.drawerState().open()
    } else {
        adScaffoldState.drawerState().close()
    }
}```


`ADState.ADScaffoldState` is a singleton Object that keeps all my states and provides methods on them
(don't know if that is good design ... is it??)

You should pass your `ADScaffoldState` instance as a parameter, not use a singleton object.  You always want to develop your widgets as self-contained reusable chunks that are pure functional transforms of their parameters.  Relying on a global singleton violates several of those principles.

Also, your `scaffoldStateClick()` does not return a unit lambda, so that's why you're getting a type error.  You probably want your code to be more like `IconButton(onClick = { scaffoldStateClick(adScaffoldState) })`