I have this java interface

public interface AggregateType<AggregateIdT> {
    AggregateIdT getId();
}

I wrote this in my kotlin class

data class Patient(val id: String, val identifier: String): AggregateType<String>

I'm assuming that kotlin would provide me a

getId()

method. However, I get this error:

Class 'Patient' must be declared abstract or implement abstract member public abstract fun getId(): String!

When I do try to implement it like this:

data class Patient(val id: String, val identifier: String): AggregateType<String> {
    override fun getId() = id
}

I get a Platform Declaration clash.

rahulsom: Because you have a data class, the getter for id is getId of type string. Because you have a data class, your patient code already looks like this:

class Patient(val id: String, val identifier: String) {
    fun getId() = id //This is of type string
    //no set because it's immutable
    fun getIdentifier() = identifier
}

adding the interface would make it look like this I believe

class Patient(val id: String, val identifier: String) : AggregateType<String> {
    fun getId() = id //This is of type string
    override fun getId() = id //Now there are two functions named getId with the same signature
    //no set because it's immutable
    fun getIdentifier() = identifier
}