What does it mean to write `static void * ptr = &ptr` in Objective-C

Well, so idea for these constants is to have some unique value, that will not repeat anywhere in the program, but we don't really care about its content.

Now, instead of coming up with some random string/number etc, we just create a pointer, and put its address as content, this way it's unique and the code is simple is nice :)

简译：
这些常量的想法是具有一些独特的价值，在程序中的任何地方都不会重复，我们并不关心它的内容。

现在，我们只是创建一个指针，而不是提供一些随机的字符串/数字等等，而是将它的地址作为内容，这样是唯一的，代码很简单很好