Kotlin/Native interoperability with Swift: generated interface with two methods having same signature

Question

I have a Kotlin multiplatform project which performs Bluetooth operations on iOS devices using the CoreBluetooth library. I am having some problems with getting the peripheral disconnected callback. On closer inspection, I see that the generated CBCentralManagerDelegateProtocol interface (which I override) has two methods with same signature.

@kotlin.commonizer.ObjCCallable public open expect fun centralManager(central: platform.CoreBluetooth.CBCentralManager, didFailToConnectPeripheral: platform.CoreBluetooth.CBPeripheral, error: platform.Foundation.NSError?): kotlin.Unit { /* compiled code */ }

@kotlin.commonizer.ObjCCallable public open expect fun centralManager(central: platform.CoreBluetooth.CBCentralManager, didDisconnectPeripheral: platform.CoreBluetooth.CBPeripheral, error: platform.Foundation.NSError?): kotlin.Unit { /* compiled code */ }

So, I can override only one of these methods. My question is am I missing something here? Like a way to override both the methods.

Answer 1

In kotlin you can't declare two functions with the same signature, differing only by argument names. But in ObjC you can.

To support this interop you can use @Suppress("CONFLICTING_OVERLOADS"), as described here in documentation.

To override different methods with clashing Kotlin signatures, you can add a @Suppress("CONFLICTING_OVERLOADS") annotation to the class.

@Suppress("CONFLICTING_OVERLOADS", "PARAMETER_NAME_CHANGED_ON_OVERRIDE")
override fun centralManager(
    central: CBCentralManager,
    didFailToConnectPeripheral: CBPeripheral,
    error: NSError?
) {
}

@Suppress("CONFLICTING_OVERLOADS", "PARAMETER_NAME_CHANGED_ON_OVERRIDE")
override fun centralManager(
    central: CBCentralManager,
    didDisconnectPeripheral: CBPeripheral,
    error: NSError?
) {
}