I’m trying to create a dynamic array which can be modified using the functions Array_Push(array, val)
& Array_Del(array, index)
. Now the current way I have this I need a variable to keep track of the size of it. My implementation of this concept is to store the data/size in a struct like so:
struct Array {
void **data;
int size;
}
However in order to read the actual array you have to type array.data[i]
which I think is a little bit redundant. My solution to this was attempting to store the size of the array in a different index. I didn’t want to store it inside [0]
as that would create a lot of confusion, so I wanted to try storing it inside of [-1]
. An obvious problem with this is that [-1]
is outside the array. What I did instead was create an array via void **array = malloc(sizeof(void*) * 2)
(the * 2
is so when you push with realloc()
it doesn’t free empty memory,) then setting the size via array[0] = (void *)0
. After that I increment the pointer to it via array += 1
. However when I try to free it free(array - 1)
, I end up freeing non malloc()
ed. I think this is just an issue with my understanding of pointers, so I wanted to ask where my logic is going wrong, along with if anybody actually knows how to do what I’m trying to do (in the title).
Maybe use a flexible struct? You can have an indeterminate array at the end (https://www.geeksforgeeks.org/flexible-array-members-structure-c/) I’d rather just use the variable in the struct though. The packing isn’t guaranteed to be right next to each other