wcwidth.h 1.4 KB

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  1. /* Internal header containing implementation of wcwidth() function.
  2. Copyright (C) 1996-2019 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
  5. The GNU C Library is free software; you can redistribute it and/or
  6. modify it under the terms of the GNU Lesser General Public
  7. License as published by the Free Software Foundation; either
  8. version 2.1 of the License, or (at your option) any later version.
  9. The GNU C Library is distributed in the hope that it will be useful,
  10. but WITHOUT ANY WARRANTY; without even the implied warranty of
  11. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12. Lesser General Public License for more details.
  13. You should have received a copy of the GNU Lesser General Public
  14. License along with the GNU C Library; if not, see
  15. <http://www.gnu.org/licenses/>. */
  16. #include <wchar.h>
  17. #include <wctype.h>
  18. #include "../wctype/wchar-lookup.h"
  19. #include "../locale/localeinfo.h"
  20. /* Table containing width information. */
  21. extern const char *__ctype32_width attribute_hidden;
  22. static __inline int
  23. internal_wcwidth (wchar_t wc)
  24. {
  25. unsigned char res;
  26. /* The tables have been prepared in such a way that
  27. 1. wc == L'\0' yields res = 0,
  28. 2. !iswprint (wc) implies res = '\xff'. */
  29. res = wcwidth_table_lookup (_NL_CURRENT (LC_CTYPE, _NL_CTYPE_WIDTH), wc);
  30. return res == (unsigned char) '\xff' ? -1 : (int) res;
  31. }