+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+ <wchar.h>.
+ BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be included
+ before <wchar.h>. */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+])
+ if test $ac_cv_have_decl_wcwidth != yes; then
+ HAVE_DECL_WCWIDTH=0
+ fi
+
+ if test $ac_cv_func_wcwidth = yes; then
+ dnl On MacOS X 10.3, wcwidth(0x0301) (COMBINING ACUTE ACCENT) returns 1.
+ dnl On OSF/1 5.1, wcwidth(0x200B) (ZERO WIDTH SPACE) returns 1.
+ dnl This leads to bugs in 'ls' (coreutils).
+ AC_CACHE_CHECK([whether wcwidth works reasonably in UTF-8 locales],
+ [gl_cv_func_wcwidth_works],
+ [
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#include <locale.h>
+/* AIX 3.2.5 declares wcwidth in <string.h>. */
+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+ <wchar.h>.
+ BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be included
+ before <wchar.h>. */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+#if !HAVE_DECL_WCWIDTH
+extern
+# ifdef __cplusplus
+"C"
+# endif
+int wcwidth (int);