flatMapIndexedTo

@JvmName(name = "flatMapIndexedIterableTo")
inline fun <T, R, C : MutableCollection<in R>> Sequence<T>.flatMapIndexedTo(destination: C, transform: (index: Int, T) -> Iterable<R>): C(source)
@JvmName(name = "flatMapIndexedSequenceTo")
inline fun <T, R, C : MutableCollection<in R>> Sequence<T>.flatMapIndexedTo(destination: C, transform: (index: Int, T) -> Sequence<R>): C(source)

Appends all elements yielded from results of transform function being invoked on each element and its index in the original sequence, to the given destination.

The operation is terminal.

Since Kotlin

1.4