CreationExtensions.swift

import UIKit

func create<T>(_ input: T? = nil, _ setup: ((T) -> Void)) -> T where T: NSObject {
    let obj = input ?? T()
    setup(obj)
    return obj
}

func create<T>(_ input: T? = nil, _ setup: ((T) -> Void)) -> T where T: UIView {
    let obj = input ?? T()
    obj.translatesAutoresizingMaskIntoConstraints = false
    setup(obj)
    return obj
}