Typed Lists

[martinfouilleul]

This adds a typed instrusive doubly-linked list type to util/lists.h.

It works the same way as the existing untyped oc_list type, but ensures that a given list can only contain items of a single type, and that these items are all linked through the same pair of next/prev pointers. This also simplifies APIs for manipulating the list and idioms like loops, since we don't have to pass the type of elements and the name of the link-pair field.

Usage is as follows:

typedef struct my_type 
{
    oc_typed_list_links links;
    int i;
} my_type;

 // declare a type for a linked list that can hold items of type my_type, linked through the links field.
typedef oc_typed_list(my_type, links) my_type_list;

// Create a list and push some items
my_type_list list = {0};
my_type t1 = {.i = 1}, t2 = {.i = 2}, t3 = {.i = 3};

oc_typed_list_push_back(&list, &t1);
oc_typed_list_push_back(&list, &t2);
oc_typed_list_push_back(&list, &t3);

// Loop through the list and print items
oc_typed_list_for(list, elt)
{
    printf("%i ", elt->i);
}