owenv

//
//  CustomLayout.swift
//  LayoutKit
//
//  Created by Owen Voorhees on 10/6/16.
//  Copyright © 2016 Owen Voorhees. All rights reserved.
//

//Lays out children using a custom set of constraints
public class CustomLayout: Layout {

owenv

protocol Equatable2 {
  //@memberwiseDerivable(mapper: equatable2Mapper, reducer: equatable2Reducer, reduceInitialResult: true)
  static func == (_: Self, _: Self) -> Bool
}

// lhs and rhs come from the derived requirement, memberKeyPath is added to the argument list
// the return type must match the reducer's argument types
// Self is replaced by generic parameter T, U is the type of the member (which conforms to the given protocol)
func equatable2Mapper<T, U: Equatable2>(_ lhs: T, _ rhs: T, memberKeyPath: KeyPath<T, U>) -> Bool {
  return lhs[keyPath: memberKeyPath] == rhs[keyPath: memberKeyPath]

owenv

Prefix * Varargs 'Splat' Operator for Arrays

• Proposal: SE-NNNN
• Authors: Owen Voorhees
• Review Manager: TBD
• Status: Pitch
• Implementation: apple/swift#25997

Introduction