Better way to do initialization in Swift

then.swift

// From https://github.com/devxoul/Then/blob/master/Sources/Then/Then.swift
// It's easy to move them into your codebase

import Foundation

public protocol Then {}

extension Then where Self: Any {
    /// Makes it available to set properties with closures just after initializing.
    ///
    ///     let label = UILabel().then {
    ///         $0.textAlignment = .Center
    ///         $0.textColor = UIColor.blackColor()
    ///         $0.text = "Hello, World!"
    ///     }
    public func then(@noescape block: inout Self -> Void) -> Self {
        var copy = self
        block(&copy)
        return copy
    }
  
    /// Makes it available to set properties with closures just after initializing and copying the value types.
    ///
    ///     let frame = CGRect().with {
    ///         $0.origin.x = 10
    ///         $0.size.width = 100
    ///     }
    public func with(_ block: (inout Self) throws -> Void) rethrows -> Self {
        var copy = self
        try block(&copy)
        return copy
    }
}

extension Then where Self: AnyObject {
    /// Makes it available to set properties with closures just after initializing.
    ///
    ///     let label = UILabel().then {
    ///         $0.textAlignment = .Center
    ///         $0.textColor = UIColor.blackColor()
    ///         $0.text = "Hello, World!"
    ///     }
    public func then(@noescape block: Self -> Void) -> Self {
        block(self)
        return self
    }
}

extension NSObject: Then {}