Question

I’m trying to cast a struct pointer to a void** for a function that takes a void**;

typedef struct {
  uint64_t   key;    // the key in the key/value pair
  void      *value;  // the value in the key/value pair
} HTKeyValue, *HTKeyValuePtr;

HTKeyValuePtr payload = (HTKeyValuePtr)malloc(sizeof(HTKeyValue));
int success = (HTKeyValuePtr) LLIteratorGetPayload(i, (void**) &payload);

gives me the warnings:

hashtable.c:161:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
hashtable.c:161:19: warning: initialization makes integer from pointer without a cast [enabled by default]

What’s going on? How do I fix this?

p.s. sorry if this is a dup of any other question. There were a lot of similar questions but I couldn’t find one that fit my situation and that I understood.

Answer 1

int success = (HTKeyValuePtr) LLIteratorGetPayload(i, (void**) &payload);

You’re assigning a pointer into an int…

In addition, google tells me the first argument to LLIteratorGetPayload should be a LLIter, which turns out to be a typedef void*. I’m guessing i is an integer. That’s the reason for the first error.