Javi JaviSoto

Following the tradition from last year, here's my complete list of all interesting features and updates I could find in Apple's OSes, SDKs and developer tools that were announced at this year's WWDC. This is based on the keynotes, the "What's New In ..." presentations and some others, Apple's release notes, and blog posts and tweets that I came across in the last few weeks.

If for some reason you haven't watched the talks yet, I really recommend watching at least the "State of the Union" and the "What's New In" intros for the platforms you're interested in. The unofficial WWDC Mac app is great way to download the videos and keep track of what you've already watched.

If you're interested, here are my WWDC 2015 notes (might be useful if you're planning to drop support for iOS 8 now and start using some iOS 9 APIs).

OSX → macOS 10.12 Sierra

Here's my own list of the interesting stuff announced during this year's WWDC, collected from the keynotes, various Apple docs, blog posts and tweets.

If you're planning to watch the videos, I really recommend this Mac app that helps you download and watch them: https://github.com/insidegui/WWDC.

OS X El Capitan

http://www.apple.com/osx/elcapitan-preview/

split view - two apps side by side on full screen

#Every Single Option Under The Sun

optimization level options
automatic crashing options
debug info options
swift internal options
swift debug/development internal options
linker-specific options
mode options

	Let's Reinvent Modern CPU Caches!

	In The Beginning, programs were hard-coded, entered directly with switches. Values would be input, and then results would output,
	but couldn't really be stored. We'll draw this like so:

	Input -> Fixed Calculations -> Output

	An early improvement in generality was the addition of storage (ENIAC eventually gained 100 words of magnetic core memory),
	leaving us with something along these lines:

	//Combine colors: add, subtract, multiply components, set and adjust color components

	import UIKit

	func + (left: UIColor, right: UIColor) -> UIColor {
	var leftRGBA = [CGFloat](repeating: 0.0, count: 4)
	var rightRGBA = [CGFloat](repeating: 0.0, count: 4)

	left.getRed(&leftRGBA[0], green: &leftRGBA[1], blue: &leftRGBA[2], alpha: &leftRGBA[3])
	right.getRed(&rightRGBA[0], green: &rightRGBA[1], blue: &rightRGBA[2], alpha: &rightRGBA[3])

	# The trick is to link the DeviceSupport folder from the beta to the stable version.
	# sudo needed if you run the Mac App Store version. Always download the dmg instead... you'll thank me later :)

	# Support iOS 15 devices (Xcode 13.0) with Xcode 12.5:
	sudo ln -s /Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/15.0 /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport

	# Then restart Xcode and reconnect your devices. You will need to do that for every beta of future iOS versions

	# (A similar approach works for older versions too, just change the version number after DeviceSupport)

	#!/bin/bash
	#
	# Faster toolchain build: skips as much as possible.
	#
	# To use this toolchain from the command line:"
	# export TOOLCHAINS=$(whoami)
	#
	# we build to the same prefix every time (instead of building
	# to a versioned prefix) because every time the prefix changes
	# everything rebuilds.

	/*
	* This is an example provided by Facebook are for non-commercial testing and
	* evaluation purposes only.
	*
	* Facebook reserves all rights not expressly granted.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NON INFRINGEMENT. IN NO EVENT SHALL
	* FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN

	Your goals are to reduce the number of things that you have to keep in your head at any given moment, and to rely as little as possible on your own ability to consistently do things right.
	If you make a thing immutable ('let' in swift), you never have to think about what happens if it changes, or what other parts of the code you'll effect if you change it.
	If you split complex functions into several smaller functions that only interact by passing arguments or getting return values, then you limit the amount of code you need to consider when hunting for a bug, and you can test each small piece separately.
	If you understand what things must be true in your code (aka invariants, for example "a person's age must be greater than 0"), and either provide no function that can cause them to be untrue, or check and crash immediately when they're untrue, then you don't have to debug issues caused by incorrect assumptions.
	If you remove possibilities (for example, Swift removes the possibility of things being nil unless