``` fun doSomething return instance of whatever is between the angle brackets below val x = lt MyType gt doSomething val y = lt MyOtherType gt doSomething ``` How should the signature of doSomething look

``` inline fun lt reified T gt doSomething T return T class constructors toList 0 call ```

``` fun doSomething return instance of whatever is between t kotlinlang #getting-started

Tony Blundell

08/12/2019, 10:03 AM

fun doSomething() {
  // return instance of whatever is between the angle brackets below
}

val x = <MyType>doSomething()
val y = <MyOtherType>doSomething()

How should the signature of doSomething look?

Thanks, but then I get a warning, Type mismatch, required Unit, found T… do I need to specify return type at the end somehow?

08/12/2019, 10:07 AM

You should return T as well

Return type of the function should be T

Tony Blundell

08/12/2019, 10:09 AM

Ah cool, and how would I reference the type inside the function? Eg, I want to pass it to something like

return mapper.readValue<T>(xmlOut)

08/12/2019, 10:09 AM

inline fun <reified T> doSomething(): T {
  return T::class.constructors.toList()[0].call()
}

Tony Blundell

08/12/2019, 10:12 AM

👍 it worked - thank you!

karelpeeters

08/12/2019, 10:41 AM

This is a pretty strange thing to do, if you know the type you can just call the constructor yourself no?

08/12/2019, 10:42 AM

Exactly, not sure what op is trying to achieve

Tony Blundell

08/12/2019, 10:42 AM

Well, I’m actually passing the type on to a Jackson XML mapper - I’m just telling the function what type I want the XML mapped back to.

Looks like this in the end:

private suspend inline fun <reified T> makeXmlRequest(req: Any): T {
        val xmlIn = mapper.writeValueAsString(req)
        val xmlOut = <http://client.post|client.post><String>(url) { body = xmlIn }
        return mapper.readValue(xmlOut)
    }

karelpeeters

08/12/2019, 10:46 AM

Oh my bad, I thought you meant to actually call the constructor.

Tony Blundell

08/12/2019, 10:46 AM

👍 no, I probably could have worded it better 🙂