根据马丁R的回答
addressOf（）不能与结构变量一起使用。字符串是一个结构，但是，当传递给需要对象的函数时，它会自动桥接到NSString。
根据nschum的回答，你可以得到一个struct、内置类型或对象引用的（堆栈）地址，如下所示：

import UIKit

func address(o: UnsafePointer<Void>) -> Int {
    return unsafeBitCast(o, Int.self)
}

func addressHeap<T: AnyObject>(o: T) -> Int {
    return unsafeBitCast(o, Int.self)
}

struct myStruct {
    var a: Int
}

class myClas {

}
//struct
var struct1 = myStruct(a: 5)
var struct2 = struct1
print(NSString(format: "%p", address(&struct1))) // -> "0x10f1fd430\n"
print(NSString(format: "%p", address(&struct2))) // -> "0x10f1fd438\n"

//String
var s = "A String"
var aa = s
print(NSString(format: "%p", address(&s))) // -> "0x10f43a430\n"
print(NSString(format: "%p", address(&aa))) // -> "0x10f43a448\n"

//Class
var class1 = myClas()
var class2 = class1
print(NSString(format: "%p", addressHeap(class1))) // -> 0x7fd5c8700970
print(NSString(format: "%p", addressHeap(class2))) // -> 0x7fd5c8700970

unsafeAddressOf(class1) //"UnsafePointer(0x7FD95AE272E0)"
unsafeAddressOf(class2) //"UnsafePointer(0x7FD95AE272E0)"

//Int
var num1 = 55
var num2 = num1
print(NSString(format: "%p", address(&num1))) // -> "0x10f1fd480\n"
print(NSString(format: "%p", address(&num2))) // -> "0x10f1fd488\n"

我发现的一件事是，如果myStruct没有值，地址将被保留不变：

struct myStruct {

}

var struct1 = myStruct()
var struct2 = struct1
print(NSString(format: "%p", address(&struct1))) // -> ""0xa000000000070252\n""
print(NSString(format: "%p", address(&struct2))) // -> ""0xa000000000070252\n""

斯威夫特2.0：
您可以使用此unsafeAddressOf(someObject)
或在Swift 3.0中：
使用withUnsafePointer(to: someObejct) { print("\($0)") }

我不确定是否有“推荐”的方法来实现这一点，但有一种方法是使用withUnsafePointer(_:_:)，如下所示：

var s: String = "foo"
withUnsafePointer(&s) { NSLog("\($0)") }

这在我的机器上打印了0x00007ffff52a011c8。