ReferenceKeyPathEditable Protocol

ReferenceKeyPathEditable.swift

enum KeyPathError: Error {
    case unableToCast(String)
}

protocol ReferenceKeyPathEditable {
    associatedtype Root
    func update<KeyPathType>(type: Root, path: PartialKeyPath<Root>, to value: KeyPathType) throws
}

extension ReferenceKeyPathEditable {
    func update<KeyPathType>(type: Root, path: PartialKeyPath<Root>, to value: KeyPathType) throws {
        guard let writableKeyPath = path as? ReferenceWritableKeyPath<Root, KeyPathType> else {
            throw KeyPathError.unableToCast("because of passed \(value) value data type")
        }
        type[keyPath: writableKeyPath] = value
    }
}