Choosing enum element using "..."

Question

Is '...' symbol is a c language keyword?

The code:

#include <stdio.h>

typedef enum {
    A=0,B,C,D,E,F,G,H,I,J,K,M
} alpha;


int main(int argc, char const *argv[])
{


    alpha table = C;

    switch (table)
    {
        case A ... D:
        /* I have never seen "..." grammar in textbook */
            printf("Oh my god\n");
            break;
        default:
            printf("default\n");
            break;
    }
    return 0;
}

Is ... allowed in C for range?

I think it is specific to gcc compiler, but I am not sure. – abhishek_naik May 19 '16 at 08:46 — abhishek_naik, May 19 '16 at 08:46

score 2 · Accepted Answer · edited Jun 20 '20 at 09:12

2

It's not standard C, but a GCC extension:

You can specify a range of consecutive values in a single case label, like this:
case low ... high:
This has the same effect as the proper number of individual case labels, one for each integer value from low to high, inclusive.

More in GCC extension: Case ranges

edited Jun 20 '20 at 09:12

Community

1
1

answered May 19 '16 at 08:48

Yu Hao

119,891
44
235
294

score 1 · Answer 2 · answered May 19 '16 at 08:47

1

This is called Case Ranges. And no, this is not a standard C feature.

It is implemented as gcc extension. This is just another way to use fall-through case statement.

answered May 19 '16 at 08:47

Sourav Ghosh

133,132
16
183
261

Choosing enum element using "..."

2 Answers2

Linked