Generics type checks and castsĭue to the type erasure, there is no general way to check whether an instance of a generic type was created with certain type arguments at runtime, and the compiler prohibits such is - checks such as ints is List or list is T (type parameter). We can perform this by transforming one collection into another, and filtering all of the elements so that only the ones that we want to match essentially like running the collection. For example, the instances of Foo and Foo are erased to just Foo. One of the more basic transformations that we can perform on a collection is to ensure that all of the elements meet certain criteria. To start new coroutines in a structured way inside a suspend function without access to the outer scope, you can create a new coroutine scope that automatically becomes a child of. The type information is said to be erased. In Structured concurrency section, they mentioned this: It’s possible to create a new scope without starting a new coroutine, by using the coroutineScope function. At runtime, the instances of generic types do not hold any information about their actual type arguments. Learn about Extension functions which allow us to add new functions to the existing classes such as Student, String and so on. The type safety checks that Kotlin performs for generic declaration usages are done at compile time. In the above example, the T type must implement both CharSequence and Comparable. The passed type must satisfy all conditions of the where clause simultaneously. Fun copyWhenGreater(list: List, threshold: T): List

Kotlin collection functions