dumb question about generics - what is wrong? ``` ...

# getting-started

[vlad.minaev]

dumb question about generics - what is wrong?

fun <T : User>gen(): List<T> = listOf(User())

[karelpeeters]

Yeah with generics I often get stuck in in abstract explanations myself.

[vlad.minaev]

Thanks, i'm just starting getting all this covariance thing

[vlad.minaev]

So, there is no way to produce subtypes of generic parameter?

[karelpeeters]

Well sometimes, depends on the situation. The stdlib emptyList has the same signature as your function, but there it is correct.

[vlad.minaev]

well, you can with reflection

actually that's the thing in my case so the method always returns instances of passed type

[karelpeeters]

How do you know the type then? You could have a signature like this: fun <T: User> gen(cls: KClass<T>): List<T>, I think that has the potential to be correct.

[vlad.minaev]

yep sorry, oversimplified the example

[vlad.minaev]

there is an argument which contains all necessary meta info (including class)

[karelpeeters]

Can't you give that object a generic parameter similar to KClass?

[vlad.minaev]

you mean smth like this?

fun <T: User> tx(producer: () -> T): T

[Muhammad Usman]

@vlad.minaev i think here is what you are seeking for .
creating instance of generic type using reified.

inline fun < reified  T : User>gen(): List<T> = listOf(T::class.java.newInstance())