[CRITICAL BUG] dynarray_get() returns pointer address as size_t

[seesee010]

Bug Description

dynarray_get() returns the memory address as a size_t instead of returning a pointer to the actual data.

Location

src/access.c lines 11-20

Current Code

size_t dynarray_get(DynArray *array, size_t index) {
    if (array == NULL) {
        return -1;
    }

    void *ptr = (array->data + index * array->element_size);  // Wrong arithmetic
    return (size_t)ptr;  // ← Returns ADDRESS, not data!
}

Problem

1. Returns pointer address as size_t (e.g., 0x7ffd5a3c1040)
2. User cannot retrieve actual value
3. Pointer arithmetic is wrong (void* should be cast to char* first)
4. Return type should be void*, not size_t

Expected Behavior

Should return a void* pointer that user can cast to their type.

Proposed Fix

void *dynarray_get(DynArray *array, size_t index) {
    if (array == NULL || index >= array->length) {
        return NULL;
    }
    
    return (char*)array->data + index * array->element_size;
}

Impact

• Severity: Critical
• Impossible to retrieve values from the array
• Makes the entire library unusable for reading data

Usage Example

// After fix:
DynArray *arr = dynarray_create(sizeof(int), 10);
int val = 42;
dynarray_set(arr, 0, &val);

int *ptr = (int*)dynarray_get(arr, 0);
printf("Value: %d\n", *ptr);  // Should print 42