#ifndef _SIMPLE_LIST_H
#define _SIMPLE_LIST_H
#ifdef __cplusplus
extern "C" {
#endif
#define remove_from_list(elem) \
do { \
(elem)->next->prev = (elem)->prev; \
(elem)->prev->next = (elem)->next; \
} while (0)
#define insert_at_head(list, elem) \
do { \
(elem)->prev = list; \
(elem)->next = (list)->next; \
(list)->next->prev = elem; \
(list)->next = elem; \
} while(0)
#define insert_at_tail(list, elem) \
do { \
(elem)->next = list; \
(elem)->prev = (list)->prev; \
(list)->prev->next = elem; \
(list)->prev = elem; \
} while(0)
#define move_to_head(list, elem) \
do { \
remove_from_list(elem); \
insert_at_head(list, elem); \
} while (0)
#define move_to_tail(list, elem) \
do { \
remove_from_list(elem); \
insert_at_tail(list, elem); \
} while (0)
#define make_empty_list(sentinal) \
do { \
(sentinal)->next = sentinal; \
(sentinal)->prev = sentinal; \
} while (0)
#define first_elem(list) ((list)->next)
#define last_elem(list) ((list)->prev)
#define next_elem(elem) ((elem)->next)
#define prev_elem(elem) ((elem)->prev)
#define at_end(list, elem) ((elem) == (list))
#define is_empty_list(list) ((list)->next == (list))
#define foreach(ptr, list) \
for( ptr=(list)->next ; ptr!=list ; ptr=(ptr)->next )
#define foreach_s(ptr, t, list) \
for(ptr=(list)->next,t=(ptr)->next; list != ptr; ptr=t, t=(t)->next)
#ifdef __cplusplus
}
#endif
#endif