Masks (macros of bits)

Question

So I'm about to finish my course in university in C programming. I want to get better at bit operations (such as creating masks) so I'll go to it:

#define BIT_I_SET(TYPE,I) ((TYPE)(1) << (I))
#define SET_BIT(NUM,I,TYPE) \
        NUM |= BIT_I_SET(I,TYPE)

I am still at the early stages and learning the syntax at the moment, I have no idea why the compiler says there's error: Severity Code Description Project File Line Suppression State Error (active) E0109 expression preceding parentheses of apparent call must have (pointer-to-) function type Project14

full program (yeah it's for synatx only):

#include <stdio.h>
#include <stdlib.h>

#define SHIFT(I,TYPE) ((TYPE)(1) << (I))
#define NEGATIVE(TYPE) (~(TYPE)(0))
#define BIT_I_SET(TYPE,I) ((TYPE)(1) << (I))
#define BIT_I_CLEAR(I,TYPE) (~((TYPE)(1)<< (I)))
#define MSB_SET(TYPE) ((TYPE)(1) << (sizeof(TYPE)*8-1)
#define SET_BIT(NUM,I,TYPE) \
        NUM |= BIT_I_SET(I,TYPE)
void main()
{
    unsigned char i, j;
    int shift = 3;
    i = 0;
    j = 0;

    SET_BIT(j, 2, unsigned char);
    printf("%d\n",sizeof(j));
    printf("%d",i);
    system("pause>null");
}

score 0 · Answer 1 · answered Jun 16 '17 at 10:18

0

change

 NUM |= BIT_I_SET(I,TYPE)

to

NUM |= BIT_I_SET(TYPE, I)

You can run just the preprocessor stage of your compiler, which expand the macros using the command:

gcc -E file.c

answered Jun 16 '17 at 10:18

skr

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Masks (macros of bits)

1 Answers1