A default protocol implementation for CustomDebugStringConvertible that uses Mirror for introspection. This is meant for debugging only.

MirrorDebugDecscription.swift

public extension CustomDebugStringConvertible {
    var debugDescription: String {
        return debugDescription()
    }
    
    func debugDescription(indentationLevel: Int = 0) -> String {
        
        let indentString = (0..<indentationLevel).reduce("") { tabs, _ in tabs + "\t" }
        
        var s = "\(self.dynamicType)"
        
        let mirror = Mirror(reflecting: self)
        let children = mirror.children
        
        if children.count == 0 {
            return "\(s) = \(debugDescription),"
        }
        
        s += " {"
        
        s = children.reduce(s) {
            reducedString, child in
            
            if let aChild = child.1 as? CustomDebugStringConvertible {
                let childDescription = aChild.debugDescription(indentationLevel + 1)
                return reducedString + "\n\(indentString)\t\(child.0!): \(childDescription)"
            } else {

                return reducedString +  "\n\(indentString)\t\(child.0!): \(child.1),"
            }
        }
        
        s = s.substringToIndex(s.characters.endIndex.predecessor())
        s += "\n\(indentString)}"
        
        return s
    }
}

// Sample usage
/*
struct Person: CustomDebugStringConvertible {
    let name: String
    let address: Address
    let children: [Person]?
}

struct Address: CustomDebugStringConvertible {
    let city: String
    let state: String
    let zip: String
    let streetNumber: String
    let streetName: String
    let suiteNumber: String?
    let randomNumber: Int
    
    init(city: String, state: String, zip: String, streetNumber: String, streetName: String, suiteNumber: String? = nil) {
        self.city = city
        self.state = state
        self.zip = zip
        self.streetNumber = streetNumber
        self.streetName = streetName
        self.suiteNumber = suiteNumber
        self.randomNumber = Int(arc4random_uniform(1000))
    }
}


let address = Address(city: "Lehi", state: "UT", zip: "84043", streetNumber: "123", streetName: "Fake st")

//print(address)

let child = Person(name: "joe", address: address, children: nil)
let person = Person(name: "matt", address: address, children: [child])


print(person)
*/