And how can I use ByteArray?

e: /home/commandertvis/IdeaProjects/communicator/communicator-zmq-c-transport/src/nativeMain/kotlin/Server.kt: (22, 43): type @[ParameterName(name = 'argument')] kotlin.ByteArray  is not supported here: doesn't correspond to any C type

Something like that:

val buffer = ByteArray(4096)
val scan = fgets(buffer.refTo(0), buffer.size, fp)

What's the way to get byte array from the C?

What do you want? Have you got some result from C code? Or you have to call some C code with ByteArray?

I want to acquire a C function with the signature similar to

(argument: ByteArray, invariant: COpaquePointer) -> ByteArray

I don’t know how it has to look like. But you cat try to do: 1. call C function with this argument and inline static function like

return MHD_start_daemon( staticCFunction { _, addr, addrLen -> ... }, ... )

2. Introduce variable> You will see something like

val apc = staticCFunction<COpaquePointer?, CPointer<sockaddr>?, socklen_t, MHD_Result>

No, I've meant "to receive such a function from C"

Have you got a C-function with return type “function”?

I want to write a Kotlin function taking a callback from C with the signature

(argument: ByteArray, invariant: COpaquePointer) -> ByteArray

.

How are you taking a callback from C?

As CPointer<CFunction<(argument: ByteArray, invariant: COpaquePointer) -> ByteArray>>. However, in the generated header the type of that parameter is void*

fun register(f: CPointer<CFunction<(argument: ByteArray, invariant: COpaquePointer) -> ByteArray>>) {
    }
    
    fun x() {
        register(staticCFunction { t, _ -> ByteArray(12) })
    }

Ok?

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