Code for a Header File in C++

#include <string.h>

const unsigned int SIZE = 10;
  
class i_arr {
    private:
        int   info[SIZE];       
        class i_arr *next;
    public:
        i_arr() 
        { 
            next = NULL;
            memset(info, '\0', sizeof(info));
        }
        ~i_arr(  );
        int& operator[] (const unsigned int index);
};