Difference between struct and class in swift4.0

difference_between_struct_class.swift

//finding memory location of stack and heap
func addressHeap<T: AnyObject>(o: T) -> Int {
    return unsafeBitCast(o, to: Int.self)
}

func addressStack(o: UnsafeRawPointer) -> Int {
    return Int(bitPattern: o)
}

//structure is a value based
struct A{
    var type: String
    
    init(type: String) {
        self.type = type
    }
}


var a = A(type: "Struct")
var a1 = a //copy the value
a1.type = "Struct1"

print(addressStack(o: &a)) // -> 4708867904
print(addressStack(o: &a1)) // -> 4708867928

print(a.type) // -> Struct
print(a1.type) // -> Struct1

print("\n")



//class is reference based
class B{
    var type: String
    
    init(type: String) {
        self.type = type
    }
}


let b = B(type: "Class")
let b1 = b // copy the address
b1.type = "Class1"

print(addressHeap(o: b)) // -> 105553116575008
print(addressHeap(o: b1)) // -> 105553116575008
print(b.type) // -> Class1
print(b1.type) // -> Class1