kone.collections/dev.lounres.kone.collections.utils/groupByTo

groupByTo

inline fun <E, K, D : KoneMutableMap<in K, KoneMutableList<E>>> KoneIterable<E>.groupByTo(destination: D, keySelector: (E) -> K): D(source)
inline fun <E, K, V, D : KoneMutableMap<in K, KoneMutableList<V>>> KoneIterable<E>.groupByTo(destination: D, keySelector: (E) -> K, valueTransform: (E) -> V): D(source)