kclass | Component inheritance and event mechanism

The parameterless constructor here only exists in the compiled Java class, and not in your Kotlin code. As far as Kotlin code is concerned, your Student class has one single constructor, with 2 optional parameters.

The Kotlin reflection API is designed to be platform-independent, so you have to use Java reflection to get the parameter constructor.

If you just want to see if you can call createInstance safely, you can just check if the class has a single constructor whose parameters are all optional. This is documented:

Creates a new instance of the class, calling a constructor which either has no parameters or all parameters of which are optional. If there are no or many such constructors, an exception is thrown.

Use clazz == Number.One::class.

Currently, you’re using clazz::class which is KClass>, the class of what was already a class.

And you forgot the ::class at the end.

However, you’re filtering to find out which subclass is the class you already know so there’s no point. You could just replace you’re whole line of code with val subclasses = listOf(Number.One::class).

The docs seem to suggest the mangling is stable:

functions using inline classes are mangled by adding some stable hashcode to the function name

As noted in the same doc, the mangling scheme has changed once with the version 1.4.30 of the Kotlin compiler, but I would consider it quite stable nonetheless. They even provided a flag to use the old scheme to generate binary compatible code, so I'm assuming it's not only unlikely to change again, but even if it does, it will surely be done with some way to keep compatibility.

In addition to setting shareNativeConnection to false, I also had to set up the LettucePoolingClientConfiguration. This combination finally increased the thread count, and I saw greatly improved performance.

This kind of operation is by default disallowed in both Java and Kotlin, because it is not type-safe. The problem is that you can take for example a function receiving an integer, store in the map and then use it later passing a string to it.

We can force the compiler to disable type guarantees by performing unchecked casts. We need to use Any instead of *:

What turned out to be the issue is that R8 bundeled with AGP 7.0 (release with Android Studio - Arctic Fox) does not handle Kotlin metadata correctly for Kotlin 1.6.0.

If using Kotlin 1.6.0 (classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.0") with AGP 7.0, then R8 version 3.0.77 is required for shrinking Kotlin libraries and for using kotlin-reflect. Updating to AGP 7.0.4 is not enough, as that version is bundled with R8 3.0.76.

To use R8 3.0.77 add the following to your settings.gradle or settings.gradle.kts:

Such an initialization of an array

It does not work, because encodeToString() resolves the type at compile time, not at runtime (it uses reified type).

Maybe there is a better way, but you can do this by acquiring a serializer manually, resolving the type at runtime:

If you are really sure that it holds TChild objects only and you won't add any other objects to it after the cast (List is read-only, not immutable), then you can just do an unchecked cast like this: