Include guards
转自:https://zh.wikipedia.org/wiki/Include防範
iOS 定义头文件 Include防范
#ifndef H_GRANDFATHER
#define H_GRANDFATHER
struct foo {
int member;
};
#endif
转自:https://zh.wikipedia.org/wiki/Include防範
#ifndef H_GRANDFATHER
#define H_GRANDFATHER
struct foo {
int member;
};
#endif