Question

I have a function which when compiled using gcc works fine, but when I compile it with g++, it gives me this error:

bon_io.cpp:In function ‘lruc_item* lruc_pop_or_create_item(lruc*)’:
bon_io.cpp:4751: error: invalid conversion from ‘void*’ to ‘lruc_item*’

Code:

typedef struct {
void      *value;
void      *key;
uint32_t  value_length;
uint32_t  key_length;
uint64_t  access_count;
void      *next;
} lruc_item;


lruc_item* lruc_pop_or_create_item(lruc *cache1) 
{
  lruc_item *item = NULL;

  if(cache1->free_items) {
  item = cache1->free_items;
  cache1->free_items = item->next;                     [LINE 4751]
   } else {
  item = (lruc_item *) calloc(sizeof(lruc_item), 1);
   }

  return item;
}

I am trying to use this function with a c++ code, that’s why need to compile it with g++, it works fine if I compile it using gcc but not with g++.

Can anyone please suggest me a way out to make this work with g++ ?

Thanks

Answer 1

How about:

cache1->free_items = (lruc_item *) item->next;

but then why is it that it gets compiled perfectly using gcc and gives
me error with g++

Because in C++ you can’t automatically convert from void * to another pointer type.