kotlin-stdlib/kotlin.collections/retainAll

retainAll

inline fun <T> MutableCollection<out T>.retainAll(elements: Collection<T>): Boolean(source)

Retains only the elements in this collection that are contained in the specified collection.

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

Since Kotlin

1.0

Return

true if any element was removed from the collection, false if the collection was not modified.

fun <T> MutableCollection<in T>.retainAll(elements: Iterable<T>): Boolean(source)

Retains only elements of this MutableCollection that are contained in the given elements collection.

Since Kotlin

1.0
fun <T> MutableCollection<in T>.retainAll(elements: Array<out T>): Boolean(source)

Retains only elements of this MutableCollection that are contained in the given elements array.

Since Kotlin

1.0
fun <T> MutableCollection<in T>.retainAll(elements: Sequence<T>): Boolean(source)

Retains only elements of this MutableCollection that are contained in the given elements sequence.

Since Kotlin

1.0
fun <T> MutableIterable<T>.retainAll(predicate: (T) -> Boolean): Boolean(source)

Retains only elements of this MutableIterable that match the given predicate.

Since Kotlin

1.0

Return

true if any element was removed from this collection, or false when all elements were retained and collection was not modified.

fun <T> MutableList<T>.retainAll(predicate: (T) -> Boolean): Boolean(source)

Retains only elements of this MutableList that match the given predicate.

Since Kotlin

1.0

Return

true if any element was removed from this collection, or false when all elements were retained and collection was not modified.