Got a question about " ```kotlinx.cinterop.staticCFunction``` " when called as a callback from C . (...

# kotlin-native

[jk2018]

Got a question about "

kotlinx.cinterop.staticCFunction

" when called as a callback from C . (Thread/SO link)

[jk2018]

https://stackoverflow.com/questions/59707350/how-to-avoid-the-error-staticcfunction-must-take-an-unbound-in-kotlin-nativ

[serebit]

As far as I know, you can't. Which sucks.

[napperley]

There are some workarounds depending on the situation. For example a Kotlin class that takes a CPointer (in the primary constructor) can be instantiated in the event handler, which is handy when the state/functionality is being passed through to the event handler as a CPointer. The class instance uses that CPointer to access the state/functionality.

[napperley]

Can find an example of that technique here: https://gitlab.com/gui-vista/samples/imageshow-sample/blob/master/src/linuxX64Main/kotlin/main.kt#L62

[Kavan]

You can pass Kotlin Function to C method by declare it outside class or object

For example :
fun example(inputPointer: COpaquePointer?) { println(inputPointer.reinterpret<String>()) } // Globally

//Then pass it like.

anyCMethod(staticCFunction(::example).reinterpret(), "hello".cstr/* input parameter for your function*/)


I explained it in simple way.