C / C++ / MFC

dl = reinterpret_cast<hci_dev_list_req>(malloc(HCI_MAX_DEV * sizeof(*dr) + sizeof(*dl)));

reinterpret_cast<hci_dev_list_req>

(hci_dev_list_req*) 

std::array<hci_dev_list, HCI_MAX_DEV> dl;

array<hci_dev_list_req, HCI_MAX_DEV> dl_array;

reinterpret_cast.

struct hci_dev_req {
    uint16_t dev_id;
    uint32_t dev_opt;
};

struct hci_dev_list_req {
    uint16_t dev_num;
    struct hci_dev_req dev_req[0];  /* hci_dev_req structures */
};

struct hci_dev_list_req *dl;
struct hci_dev_req *dr;
int dev_id = -1;
int i, sk, err = 0;


dl = malloc(HCI_MAX_DEV * sizeof(*dr) + sizeof(*dl));

struct hci_meta {
   std::array<hci_dev_req,HCI_MAX_DEV> my_hci_list;
   hci_dev_req& operator[](int i) {
      return my_hci_list[i];
   }
   hci_dev_list_req my_hci_req;
};
void foo() {
   hci_meta dl; // use new if you must, but so far I see no need
   hci_dev_list* dr = dl.my_hci_req;

   ...
   // use some hci element from the list:
   hci_dev_req current_dev_req = dl[i]; // invokes hci_meta::operator[](int)
   ...
}

struct hci_meta {
   hci_dev_req my_hci_list[HCI_MAX_DEV];
   hci_dev_req& operator[](int i) {
      return my_hci_list[i];
   }
   hci_dev_list_req my_hci_req;
};