Why C compiler wouldn't accept this conditional assignment?

Question

I was wondering why binary numbers can't be used with bitwise operators?

//works
msgSize = (*(msgbody+1) & 0x80)?*(msgbody+5):*(msgbody+3); 

//doesn't compile
msgSize = (*(msgbody+1) & 0b10000000)?*(msgbody+5):*(msgbody+3); 

Answer 1

Binary literals aren't supported in C; If they're available, they're an extension. I would suggest that your compiler is emitting an error because it doesn't recognise the binary literal 0b10000000. Hence, your compiler probably emits an error on this, too:

int main(void) {
    int msgSize = 0b10000000;
    return 0;
}

I would suggest using 0x80 or 1 << 7 instead.