intrinsicContentSize.swift

//: A UIKit based Playground for presenting user interface
  
import UIKit
import PlaygroundSupport

final class MyViewController : UIViewController {
    
    weak var titleLabel: UILabel!
    
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white

        let label = UILabel()
        label.backgroundColor = .red
        label.text = "Hello World!"
        label.textColor = .black
        label.translatesAutoresizingMaskIntoConstraints = false
        titleLabel = label
        
        view.addSubview(label)
        
        NSLayoutConstraint.activate([
            label.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            label.centerYAnchor.constraint(equalTo: view.centerYAnchor)
        ])
        
        self.view = view
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        
        print("view intrinsic content size: \(view.intrinsicContentSize)")
        print("titleLabel intrinsic content size: \(titleLabel.intrinsicContentSize)")
    }
    
}
// Present the view controller in the Live View window
PlaygroundPage.current.needsIndefiniteExecution = true
PlaygroundPage.current.liveView = MyViewController()