The dev09 don't allow delegation in

state

, there is some special technical reason?

It should, but you need to additionally import the delegate functions:

import androidx.compose.getValue
import androidx.compose.setValue

Alt+enter in the IDE should set you up. It moved to inline delegate functions to be compatible with the kotlin 1.4 optimizations

oh, ok! now is a extension funtion

inline operator fun <T> State<T>.getValue(thisObj: Any?, property: KProperty<*>): T = value

Thanks!