WebWe can't perform any checks to verify what types of element List contains: /* Compile time error: cannot check instance of erased type: List */ if (collection is List) { //... } The problem occurs because a check is performed at runtime where information about type parameters is not available. WebSep 29, 2024 · fun checkInfo(items:List) { if(items is List) { // (1) println("item is a list of Strings") } } (1) This line won’t compile, the error is “Cannot check for instance of erased type” The is keyword doesn’t work on generic types at runtime, the smart cast breaks because of type erasure.
Cannot check for instance of erased type: …
WebJun 8, 2024 · I’m following a rough interpretation of the Actor model with Kotlinx’s coroutine BroadcastChannels.These channels are listened to by several actors, so my design right now is for the containing class of each actor to take in a Channels object, like so:. class Channels { val myChannel = BroadcastChannel(1) val myOtherChannel = … WebFeb 6, 2024 · fun getService (): T? { val service = services.firstOrNull { s -> s is T } if (service != null) { return service as T } return null } On s is T, the compiler complains "Cannot check for instance of erased type: T". How can I make this work without inlining, which would require the list of services to be made public? design-patterns great email welcoming to the team
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WebDec 6, 2024 · Please take a look at the explanation of type erasure and type checks for generic types in the language reference: Type erasure and generic type checks. Basically, you cannot do that sort of check because the instances of SettingsKeyContractWithType do not hold any information about their actual type argument at runtime.. An option that … WebThe problem occurs because a check is performed at runtime where information about type parameters is not available. Kotlin, however, as opposed to Java, does not allow us to declare a raw type (a generic type that is not parametrized with a type argument): SimpleList<> ... WebOct 15, 2009 · At runtime, the type is gone, there is no way to check for it. You could catch it by making a factory for your object like this: public static MyObject createMyObject (Class type) { return new MyObject (type); } And then in the object's constructor store that type, so variable so that your method could look like this: flight type dishwasher sustainability