Hi, I'm having some problems with generics: How do...

# announcements

[Fré Dumazy]

Hi, I'm having some problems with generics:
How do I create a method that accepts
<T: MyObject> myMethod(arg: MyWrapper<T>) and
<T: MyObject> myMethod(arg: MyWrapper<Array<T>>)
If I try this in 2 methods with the same name, it says "The following declarations have the same JVM signature"

[diesieben07]

It's a platform limitation, you can work around it by annotating one method with @JvmName and provide an alternative platform name to use.

[Fré Dumazy]

oh, okay. Thanks, it works 🙂

[karelpeeters]

The problem behind this is that generics are erased, they don't exist at runtime, so both methods would have the same signature.

[Fré Dumazy]

Hmm, interesting. I'm reading kotlin in action, but haven't got to the generics part yet. Hopefully it will explain this issue and give an idea of the inner workings

[gildor]

@Fré Dumazy It’s because of generics implementation on JVM, you can find a lot of explanation if google “java type erasure”.

[mannodermaus]

That @JvmName approach to getting around the limitation is actually pretty genius and handy, esp. if you don’t have to interop