// RUN: %target-swift-frontend -primary-file %s -emit-ir // https://github.com/apple/swift/issues/47194 extension Dictionary { init(grouping elements: S, by keyForValue: (S.Iterator.Element) -> Key) where Array == Value { self = [:] for value in elements { var values = self[keyForValue(value)] ?? [] values.append(value) self[keyForValue(value)] = values } } }