Swift 3 Reflection - Iterating over properties

Trying to write a convenience toString() method that lists all properties and their assigned values of an object.

class FooModel
{
    func toString() -> String
    {
        var result = "[\(String(describing: type(of: self))) "
        let mirror = Mirror(reflecting: self)
        mirror.children.forEach
        {
            child in
                result += "\(child.label): \(child.value), "
        }
        return "\(result)]"
    }
}

class FooProject : FooModel
{
    var id = 0
    var name = ""
    var announcement:String?
    var showAnnouncement = false
    var isCompleted = false
    var completedOn:String?
    var suiteMode = 0
    var url = ""
}

Output:

[FooProject Optional("id"): 0, Optional("name"): , Optional("announcement"): nil, Optional("showAnnouncement"): false, Optional("isCompleted"): false, Optional("completedOn"): nil, Optional("suiteMode"): 0, Optional("url"): , ]

First, it doesn't list the actual values but the default values. Why is that? Second, is there a way to get rid of the Optional encapsulation?