Editing Pointer swizzling (section)

==Example==
It is easy to create a [[linked list]] data structure using elements like this:

<syntaxhighlight lang=c>
struct node {
        int data;
        struct node *next;
};
</syntaxhighlight>

But saving the list to a file and then reloading it will (on most operating systems) break every link and render the list useless because the nodes will almost never be loaded into the same memory locations. One way to usefully save and retrieve the list is to assign a unique id number to each node and then '''unswizzle''' the pointers by turning them into a field indicating the id number of the next node:

<syntaxhighlight lang=c>
struct node_saved {
        int data;
        int id_number;
        int id_number_of_next_node;
};
</syntaxhighlight>

Records like these can be saved to a file in any order and reloaded without breaking the list. Other options include saving the file offset of the next node or a number indicating its position in the sequence of saved records, or simply saving the nodes in-order to the file.

After loading such a list, finding a node based on its number is cumbersome and inefficient (serial search). Traversing the list was very fast with the original "next" pointers. To convert the list back to its original form, or '''swizzle''' the pointers, requires finding the address of each node and turning the ''id_number_of_next_node'' fields back into direct pointers to the right node.