Array to Linked List

array_to_list.cpp

/*C++*/
template<typename T>
struct ListNode {
    next *ListNode = nullptr;
    T data;
};

template <typename T>
ListNode* vec_to_list(std::vector<T> array) {
   ListNode* root = new ListNode;
   current = root;
   for(int i=0; i<array.size(); ++i) {
       current->data = x;
       if (i < array.size() - 1) {
        current = current->next;
        current->next = new ListNode;
       }
   }
   return root;
}

/*C*/
struct ListNode {
    next *ListNode = nullptr;
    void* data;
};

ListNode* new_list_node(void* data, size_t size)
{
  ListNode root = malloc(sizeof(ListNode));
  if (!root) return NULL; //bad alloc
  if (data) {
    root->data = malloc(size);
    if (!(root->data)) { free(root); return NULL;} //bad alloc
    memcpy(root->data,data,size);
  }
  return root;
}

void free_list_node(ListNode* n)
{
  if (!n) return;
  if (n->data) free(n->data);
  free(n);
}

//array : pointer to array first element
//type_size: size of array element type in bytes
//len: number of elements in array
ListNode* array_to_list(void* array, size_t type_size, size_t len) {
     ListNode* root = new_list_node(NULL,0);
     ListNode* current = root;
     for(int i=0; i<len; ++i) {
        current->data = malloc(type_size);
        if (current->data == NULL) return NULL; //bad alloc
        memcpy(current->data, array,type_size);
        if (i < len - 1) {
            current-> next = new_list_node(NULL,0);
            current = current->next;
        }
     }
     return root;
}