How to typecast preprocessor (macros) to output int

问题

I have a very simple macro for which I want to typecast its output to int only. How to do that?

#define Numbits(A) (sizeof(A)*CHAR_BIT)

I tried:

#define int Numbits(A)({int val; val = sizeof(A)*CHAR_BIT; return val;})

but it also doesn't work

回答1:

Are you saying that #define Numbits(A) (int)(sizeof(A)*CHAR_BIT) didn't work?

来源：https://stackoverflow.com/questions/31443484/how-to-typecast-preprocessor-macros-to-output-int