flatMapIndexedTo
inline fun <T, R, C : MutableCollection<in R>> Sequence<T>.flatMapIndexedTo(destination: C, transform: (index: Int, T) -> Iterable<R>): C(source)
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.