wcsmbs/wcwidth.h

   1 /* Internal header containing implementation of wcwidth() function.
   2    Copyright (C) 1996, 1997, 1999 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
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <wchar.h>
  22 #include <wctype.h>
  23 #include "../wctype/cname-lookup.h"
  24
  25 /* Array containing width information.  */
  26 extern unsigned char *__ctype_width;
  27
  28 /* If the program is compiled without optimization the following declaration
  29    is not visible in the header.   */
  30 extern unsigned int *__ctype32_b;
  31
  32 static __inline int
  33 internal_wcwidth (wint_t ch)
  34 {
  35   size_t idx;
  36
  37   if (ch == L'\0')
  38     return 0;
  39
  40   idx = cname_lookup (ch);
  41   if (idx == ~((size_t) 0) || (__ctype32_b[idx] & _ISwprint) == 0)
  42     return -1;
  43
  44   return (int) __ctype_width[idx];
  45 }