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kotlinlang

`KType.classifier` will give you that, but it does not have to be a `KClass`, it could be a `KTypeParameter`. There is also `KType.jvmErasure`, which will loose type information though.

I still can't do `when(consP.type.classifier) { is kotlin.String -&gt; \\... }` though, as I still have incompatible types.

Yes, `classifier` is a `KClassifier?`. The type might not be a pure `KClass`.

Hmm, perhaps what I want is not possible then. I really just want to know if my constructor's parameter accepts a kotlin.String or not. If it does, I'll just pass in my string value. If it does not, I'll call another function.

Well, the problem is not as simple as you might think.
Assume you have this class:
```
class MyClass&lt;T&gt;(value: T)
```

You can pass in a `String` only if `T` is `String`, but that is not knowable at runtime, since generics are erased.

OK. I'll have a think about my approach. I think Spring MVC manages it, somehow, but it's been a while since I've written much Spring code.

Spring will "blow up" in the scenario I mentioned as well. If you want Spring's behavior, `jvmErasure` is what you want I think.