what s the best way to do an `is` style check when the type is erased and i can t use `reified` is it to take in a `KClass` as an arg and do something like ```fun lt T gt matches value KClass lt V gt Boolean = Class class java kotlin == value``` and call it via `matches MyClass class java kotlin `

I m not a pro at reflection y stuff either sweat smile I tend to avoid it

``` fun matches value Any type KClass lt gt Boolean = type java isAssignableFrom value class java ```

You can use `KClass lt gt ` s `isInstance Any ` which is basically a dynamic `is`

what s the best way to do an `is` style check when the type kotlinlang #announcements

07/23/2019, 9:58 PM

what's the best way to do an

is

style check when the type is erased (and i can't use

reified

)? is it to take in a

KClass

as an arg and do something like:

fun<T> matches(value: KClass<V>): Boolean = Class::class.java.kotlin == value

and call it via

matches(MyClass::class.java.kotlin)

07/23/2019, 10:00 PM

Do you really really need the

is

check to happen?

07/23/2019, 10:00 PM

i do, it's for a predicate that's based on an instance check

07/23/2019, 10:01 PM

You're solution is close but it doesn't handle subclasses.

I'm not a pro at reflection-y stuff either. 😅 I tend to avoid it.

07/23/2019, 10:02 PM

i had used reified with inlining--which does work, but unfortunately ran into a bug similar to this one https://youtrack.jetbrains.com/issue/KT-32749

yeah good catch on the subclass thing, i would want those to match

karelpeeters

07/23/2019, 10:36 PM

fun matches(value: Any, type: KClass<*>): Boolean =
    type.java.isAssignableFrom(value::class.java)

07/24/2019, 6:13 AM

You can use `KClass<*>`’s

isInstance(Any?)

which is basically a dynamic

is

07/24/2019, 4:34 PM