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The C and C++ Include Header Files

cat -n /usr/include/python3.14/internal/pycore_llist.h

     1	// A doubly-linked list that can be embedded in a struct.
     2	//
     3	// Usage:
     4	//  struct llist_node head = LLIST_INIT(head);
     5	//  typedef struct {
     6	//      ...
     7	//      struct llist_node node;
     8	//      ...
     9	//  } MyObj;
    10	//
    11	//  llist_insert_tail(&head, &obj->node);
    12	//  llist_remove(&obj->node);
    13	//
    14	//  struct llist_node *node;
    15	//  llist_for_each(node, &head) {
    16	//      MyObj *obj = llist_data(node, MyObj, node);
    17	//      ...
    18	//  }
    19	//
    20	
    21	#ifndef Py_INTERNAL_LLIST_H
    22	#define Py_INTERNAL_LLIST_H
    23	
    24	#include <stddef.h>
    25	
    26	#ifdef __cplusplus
    27	extern "C" {
    28	#endif
    29	
    30	#ifndef Py_BUILD_CORE
    31	#  error "Py_BUILD_CORE must be defined to include this header"
    32	#endif
    33	
    34	struct llist_node {
    35	    struct llist_node *next;
    36	    struct llist_node *prev;
    37	};
    38	
    39	// Get the struct containing a node.
    40	#define llist_data(node, type, member) (_Py_CONTAINER_OF(node, type, member))
    41	
    42	// Iterate over a list.
    43	#define llist_for_each(node, head) \
    44	    for (node = (head)->next; node != (head); node = node->next)
    45	
    46	// Iterate over a list, but allow removal of the current node.
    47	#define llist_for_each_safe(node, head) \
    48	    for (struct llist_node *_next = (node = (head)->next, node->next); \
    49	         node != (head); node = _next, _next = node->next)
    50	
    51	#define LLIST_INIT(head) { &head, &head }
    52	
    53	static inline void
    54	llist_init(struct llist_node *head)
    55	{
    56	    head->next = head;
    57	    head->prev = head;
    58	}
    59	
    60	// Returns 1 if the list is empty, 0 otherwise.
    61	static inline int
    62	llist_empty(struct llist_node *head)
    63	{
    64	    return head->next == head;
    65	}
    66	
    67	// Appends to the tail of the list.
    68	static inline void
    69	llist_insert_tail(struct llist_node *head, struct llist_node *node)
    70	{
    71	    node->prev = head->prev;
    72	    node->next = head;
    73	    head->prev->next = node;
    74	    head->prev = node;
    75	}
    76	
    77	// Remove a node from the list.
    78	static inline void
    79	llist_remove(struct llist_node *node)
    80	{
    81	    struct llist_node *prev = node->prev;
    82	    struct llist_node *next = node->next;
    83	    prev->next = next;
    84	    next->prev = prev;
    85	    node->prev = NULL;
    86	    node->next = NULL;
    87	}
    88	
    89	// Append all nodes from head2 onto head1. head2 is left empty.
    90	static inline void
    91	llist_concat(struct llist_node *head1, struct llist_node *head2)
    92	{
    93	    if (!llist_empty(head2)) {
    94	        head1->prev->next = head2->next;
    95	        head2->next->prev = head1->prev;
    96	
    97	        head1->prev = head2->prev;
    98	        head2->prev->next = head1;
    99	        llist_init(head2);
   100	    }
   101	}
   102	
   103	#ifdef __cplusplus
   104	}
   105	#endif
   106	#endif /* !Py_INTERNAL_LLIST_H */