function pointer as structure member

Question

    void TestOperation_Init(const void *Ptr)        
     {
        /*do something*/
     }

    struct FeatureStruct 
    {
        const Select *S;
        void (*Init)(const void *Ptr);
    };

    sturct Cnf
    {
        const FeatureStruct *Feature;
    };


    const Cnf Cnf_1[0]=
    {
       &FeatureStruct_1[0],
    };

    const FeatureStruct FeatureStruct_1[0]=
    {
    (Select*)&TestStruct,
    TestOperation_Init,
    };

    const Cnf *CnfPtr;

   void Main_Init(const Cnf *MainCnfPtr)
   {
    CnfPtr=MainCnfPtr;
    CnfPtr->Feature->Init(CnfPtr->Feature->S);
   }

User will call

Main_Init(&Cnf_1[0]);

Now if I want to access member of feature struct

I write it like this

CnfPtr->Feature->Init(CnfPtr->Feature->S);

But compiler gives error at "Feature->Init" and Feature->S" that left side of -> is not struct

If I write like this

CnfPtr->Feature.Init(CnfPtr->Feature.S);

It works and gives not error.

My question is, What is correct way to access function pointer which is memeber of another structure ? Because Feature is pointer to the structure and it points to "Init" function pointer.

Thank you in advance.

Answer 1

Take a look at the below code snippet which will show how to access function pointers within structure.Please make a note that C is case sensitive. In your code you tend to just ignore it.

Question:

What is correct way to access function pointer which is memeber of another structure ?

    struct FeatureStruct 
    {
    void (*Init)();
    };

    struct Cnf
    {
     struct FeatureStruct *Feature;
    };

void func()
{
    printf("Hi\n");
}


int main(void) {
    struct Cnf *CnfPtr;
    CnfPtr = malloc(sizeof(struct Cnf));
    CnfPtr->Feature = malloc(sizeof(struct FeatureStruct));
    CnfPtr->Feature->Init = func;/* Initialize your pointer */
    CnfPtr->Feature->Init();
    return 0;
}