Is there a way to declare a function argument to take an anonymous enum?

Question

If I have an anonymous enum, is there any way to pass a value of that type to a function? For example,

typedef struct {
    enum { On, Off } status;
    int max_amps;
} SWITCH;

void make_switches(){
    SWITCH switch1 = createSwitch( On, 15 );
    SWITCH switch2 = createSwitch( Off, 20 );
}

SWITCH* createSwitch( ??? status, int max_amps ){
    SWITCH* new_switch = malloc( sizeof( SWITCH ) );
    new_switch->status = status;
    new_switch->max_amps = max_amps;
    return new_switch;
}

I would like to pass the value of the anonymous enum into the createSwitch() function. Is there any way to do this?

I'm sure you already thought of this, but my suggestion is to promote the `enum` to be a global, named type. — Tom Karzes, Apr 12 '19 at 03:52
The value of an enumeration is similar to an integer, you can accept `status` as any type of integer — liamcomp, Apr 12 '19 at 03:52
Replacing `???` with `typeof(On)` is a really bad idea for many reasons, not the least of which is that it isn't mentioned in the C specification. See also: https://stackoverflow.com/questions/12081502/typeof-operator-in-c — user3386109, Apr 12 '19 at 03:52
@user3386109: I guess I'm blind; where do you see`typeof(On)` ? — Mark Benningfield, Apr 12 '19 at 03:56
Consider [What is the size of an enum in C?](https://stackoverflow.com/q/366017/2410359): the size of the argument is not known. — chux - Reinstate Monica, Apr 12 '19 at 04:25

P.W · Accepted Answer · 2019-04-12T10:53:30.917

10

As others have suggested, you can simply use an int in the place of ???.

This is because as per 6.7.2.2/3 of C11 standard (Committee draft):

The identifiers in an enumerator list are declared as constants that have type int and may appear wherever such are permitted.

edited Apr 12 '19 at 10:53

answered Apr 12 '19 at 04:26

P.W

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Is there a way to declare a function argument to take an anonymous enum?

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