import Cocoa

func address(of object: UnsafeRawPointer) -> String {
    let addr = Int(bitPattern: object)
    return String(format: "%p", addr)
}

struct Foo {
    public var baz: String
}

struct Bar {
    public private(set) var baz: String
    
    mutating func updateBaz(with text: String) {
        baz = text
    }
}

var foo = Foo(baz: "yankee")
print("Foo holds \(foo.baz)", address(of: &foo))
foo.baz = "doodle"
print("Foo holds \(foo.baz)", address(of: &foo))

var bar = Bar(baz: "sporty")
print("Bar holds \(bar.baz)", address(of: &bar))
bar.updateBaz(with: "spice")
print("Bar holds \(bar.baz)", address(of: &bar))