Ben-G

struct StructTest {}
class ClassTest {}

class WillBeConstrained<T> {}

// Error:  type 'T' constrained to non-protocol type 'StructTest'
extension WillBeConstrained where T: StructTest {

}

Ben-G

//: Playground - noun: a place where people can play

import Cocoa

let a: Int? = 3
let b: Int? = 3

public func equateThem <T: Equatable>(lhs : Optional<T>, rhs : Optional<T>) -> Bool {
    return lhs! == rhs!
}

Ben-G

func map<A,B,C>(f1: (B) -> C, f2: (A) -> B) -> (A) -> C {
    return { f1(f2($0)) }
}


func addOne(i: Int) -> Int {
    return i + 1
}

func convertToString(i: Int) -> String {

Ben-G

//: Playground - noun: a place where people can play

import UIKit

struct Person {
    let name: String
    let age: Int
}

struct Car {

Ben-G

//: Playground - noun: a place where people can play

import Cocoa

protocol Action {}

final class Store<State> {
    typealias Reducer = (Action, State) -> (State, [Any])

    var state: State

Ben-G

// Don't actually do this...
func lift<A, B, C>(input: (A, B, C)) -> (A!, B!, C!) {
    return (Optional(input.0)!, Optional(input.1)!, Optional(input.2)!)
}

Ben-G

//
//  CoreDataStackInMemory.swift
//  TripPlanner
//
//  Created by Benjamin Encz on 7/20/15.
//  Copyright © 2015 Make School. All rights reserved.
//

// Structure is inspired by: http://martiancraft.com/blog/2015/03/core-data-stack/, Thanks!

Ben-G

import Foundation

struct Term {
  let offset: Int
  let value: String
}

let term = Term(offset: 0, value: "")
let output = generateEquatable(term)
print(output)

Ben-G

// Thanks to @jckarter for pointing that this is just Optional's map implementation... 
{ $0.map(f) }

/// Takes a function with non-optional input and non-optional return and lifts it to a function
/// with optional input and optional return. 
/// The lifted function will return `nil` iff the input is `nil`, otherwise the input will be 
/// applied to the original function which will return a non-`nil` value.
public func liftToOptional<T,U>(_ f: @escaping (T) -> U) -> (T?) -> U? {
    return { arg in
        guard let arg = arg else { return nil }

Ben-G

//: Playground - noun: a place where people can play

import Foundation

let arr = [1,5,7,8]

let pointer = UnsafeMutablePointer<[Int]>.alloc(4)
pointer.initialize(arr)

let x = pointer.memory[3]