Question

I have the following data types declaration.

    typedef struct{
            int aa;
    }A;

    typedef struct{
        int bb;
    }B;

    typedef struct{

        union {
                A a;
                B b;
        }*D;

        int other;
    }myType;

    //Now I want to pass the array "D" and the variable "other" to a function 
    // that will use them to construct "myType"
    // How can I pass D as parameter? what whill be its type?

    //I want to have a function like the following with "?" filled. 

        callFunction(? d, int other){
            //construct "myType"
            myType typ;
            typ.D     = d;
            typ.other = other; 
        }

I have tried to declare the union outside the “mytype” struct, and then use D* d; in “mytype” struct
in that case I am having this error

error: expected specifier-qualifier-list before ‘D’

The code is as follows:
//struct A and B are declared above

    union {
            A a;
            B b;
    }D;

    typedef struct{            
            D* d;            
            int other;
    }myType;

Any help will be appreciable,

thanks.

Answer 1

typedef union {
   A a;
   B b;
} D;

typedef struct{
   D d;
   int other;
}myType;

callFunction(D *d, int other)

or

union D {
   A a;
   B b;
};

typedef struct{
   union D d;
   int other;
}myType;

callFunction(union D *d, int other)

The body of callFunction will be the same for both:

{
            //construct "myType"
            myType typ;
            typ.D     = *d;
            typ.other = other; 
}