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retainAll

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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Licensed under the Apache License, Version 2.0.
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/retain-all.html