containsAll

inline fun <T> Collection<T>.containsAll(
    elements: Collection<T>
): Boolean
(source)

Checks if all elements in the specified collection are contained in this collection.

Allows to overcome type-safety restriction of containsAll that requires to pass a collection of type Collection<E>.

import kotlin.test.*

fun main(args: Array<String>) {
//sampleStart
val collection = mutableListOf('a', 'b')
val test = listOf('a', 'b', 'c')
println("collection.containsAll(test) is ${collection.containsAll(test)}") // false

collection.add('c')
println("collection.containsAll(test) is ${collection.containsAll(test)}") // true
//sampleEnd
}