c - #定义错误: expected declaration specifiers or '...' before '(' token

Question

你知道为什么我会从这段代码中得到这些错误吗？

#define container_of(ptr, type, member) ({\
    const typeof( ((type *)0)->member ) *__mptr = (ptr);\
    (type *)( (void *) ( (char *)__mptr - offsetof(type,member) ) );})

error: expected declaration specifiers or '...' before '(' token
error: '__mptr' undeclared (first use in this function)

Answer 1

感谢您的帮助!

用两侧各有两个下划线的 typeof 替换 'typeof' 解决了问题。