CODEWITHSUNDEEP
kotlingenerics
ever alian
ever alian

Reputation: 1060

Kotlin - Override a function with Generic return type

I have an interface. I want to make the return type of one of the function in that interface as generic type. Depend on how it is going to override, the return type will determine. When I try below code, I get errors Conflicting overloads: . I am new to Kotlin.

interface Loader<T> {

     fun <T> doSomething(inputParams: Map<String, String> = emptyMap()): T?

     fun cancelSomething(inputParams: Map<String, String> = emptyMap())
}

class LoaderHandler<MutableMap<String, String>> (private val foo: Foo) : Loader<MutableMap<String, String>> {

    override fun doSomething(inputParams: Map<String, String>): MutableMap<String, String>? { 
        // some code goes here.
        return mapOf("x" to "y")
    }

    override fun cancelSomething (inputParams: Map<String, String>) {
        println("cancelSomething")
    }

How can I implement the doSomething(...) function with return type of Map.

Upvotes: 0

Views: 904

Answers (1)

Louis Wasserman
Louis Wasserman

Reputation: 198024

Delete <T> in

 fun <T> doSomething(inputParams: Map<String, String> = emptyMap()): T?

It is not doing what you think it is.

Additionally,

class LoaderHandler<MutableMap<String, String>> (private val foo: Foo) : Loader<MutableMap<String, String>> {

should be

class LoaderHandler(private val foo: Foo) : Loader<MutableMap<String, String>> {

Upvotes: 1

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