结构体里嵌套一个结构体数组指针

and so on, and so forth. There are all kinds of ways to get an invalid pointer value in C. My favourite has got to be the guy who tried to "save" his objects by writing their addresses to a file. Strangely, when he read back those pointer values during a different run of the program, they didn't point to his objects any more. Fancy, that.

But that's just what wild means to me. Since it's not a normative term, it means whatever the person who spoke or wrote it meant it to mean. Ask him or her.