flatMapIndexedTo

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

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

Since Kotlin

1.4