wcwidth.h 1.4 KB

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  1. /* Internal header containing implementation of wcwidth() function.
  2. Copyright (C) 1996-2026 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, see
  14. <https://www.gnu.org/licenses/>. */
  15. #include <wchar.h>
  16. #include <wctype.h>
  17. #include "../wctype/wchar-lookup.h"
  18. #include "../locale/localeinfo.h"
  19. /* Table containing width information. */
  20. extern const char *__ctype32_width attribute_hidden;
  21. static __inline int
  22. internal_wcwidth (wchar_t wc)
  23. {
  24. unsigned char res;
  25. /* The tables have been prepared in such a way that
  26. 1. wc == L'\0' yields res = 0,
  27. 2. !iswprint (wc) implies res = '\xff'. */
  28. res = wcwidth_table_lookup (_NL_CURRENT (LC_CTYPE, _NL_CTYPE_WIDTH), wc);
  29. return res == (unsigned char) '\xff' ? -1 : (int) res;
  30. }