Auto layout in playground

gistfile1.txt

// Auto layout in a Swift Playground (for iOS).

import UIKit

var v = UIView()
v.frame = CGRectMake(0, 0, 200, 200)

var b1 = UIButton()
b1.setTitle("Click Me", forState:UIControlState.Normal)
b1.setTitleColor(UIColor.blueColor(), forState: UIControlState.Normal)
b1.setTranslatesAutoresizingMaskIntoConstraints(false)
v.addSubview(b1)

var b2 = UIButton()
b2.setTitle("Click Me Too", forState:UIControlState.Normal)
b2.setTitleColor(UIColor.blueColor(), forState: UIControlState.Normal)
b2.setTranslatesAutoresizingMaskIntoConstraints(false)
v.addSubview(b2)

var views = Dictionary<String, UIView>()
views["b1"] = b1
views["b2"] = b2

v.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-[b1]-|", options: nil, metrics: nil, views: views))

v.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-[b2]-|", options: nil, metrics: nil, views: views))

v.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-[b1]-[b2]", options: nil, metrics: nil, views: views))

v.layoutIfNeeded()

b1.frame
b2.frame
v.frame

v

Needs to be an iOS project for this to work. Same method would work for AppKit, but class names would be different.

You can set the Platform (iOS or OS X) in the file explorer: View -> Utilities -> Show File Explorer