def changed_value
import bend-collections@1.0.0.0/src/containers/balanced_search_tree.bend as BalancedSearchTreeimport Base
437def changed_value(~K: Data, ~V: Data, ~cmp: K -> K -> Cmp, r: TreeMap<K, V, cmp> & Maybe<&2, V>) -> TreeMap<K, V, cmp> & Bool:
438 match r:
439 case Tuple{m, None{}}:
440 (m, False{})
441 case Tuple{m, Some{old}}:
442 (m, True{})