insremque.c 1.7 KB

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  1. /* Copyright (C) 1992, 1995, 1996 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Library General Public License as
  5. published by the Free Software Foundation; either version 2 of the
  6. License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Library General Public License for more details.
  11. You should have received a copy of the GNU Library General Public
  12. License along with the GNU C Library; see the file COPYING.LIB. If not,
  13. write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  14. Boston, MA 02111-1307, USA. */
  15. #include <features.h>
  16. #include <stddef.h>
  17. #include <search.h>
  18. #ifdef L_insque
  19. /* Insert ELEM into a doubly-linked list, after PREV. */
  20. void
  21. insque (void *elem, void *prev)
  22. {
  23. struct qelem *next = ((struct qelem *) prev)->q_forw;
  24. ((struct qelem *) prev)->q_forw = (struct qelem *) elem;
  25. if (next != NULL)
  26. next->q_back = (struct qelem *) elem;
  27. ((struct qelem *) elem)->q_forw = next;
  28. ((struct qelem *) elem)->q_back = (struct qelem *) prev;
  29. }
  30. #endif
  31. #ifdef L_remque
  32. /* Unlink ELEM from the doubly-linked list that it is in. */
  33. void
  34. remque (void *elem)
  35. {
  36. struct qelem *next = ((struct qelem *) elem)->q_forw;
  37. struct qelem *prev = ((struct qelem *) elem)->q_back;
  38. if (next != NULL)
  39. next->q_back = prev;
  40. if (prev != NULL)
  41. prev->q_forw = (struct qelem *) next;
  42. }
  43. #endif