Question

Is it safe to convert an int pointer to void pointer and then back to int pointer?

main()
{
    ...
    int *a = malloc(sizeof(int));
    ...
    *a=10;
    func(a);
    ...
}

void func(void *v)
{
    int x=*(int *)v;
    ...
}

Is this a valid way of getting the integer value back in the function?

Answer 1

Yes, it is safe. The Standard says so (6.3.2.3/1)

A pointer to void may be converted to or from a pointer to any
incomplete or object type. A pointer to any incomplete or object
type may be converted to a pointer to void and back again;
the result shall compare equal to the original pointer.