+# if defined(__WINDOWS__)
+# define CHRBITS 16
+# define CHR_MAX 0xfffe
+# else /* !__WINDOWS__ */
+# if defined(__MACH__)
+# define CHRBITS 32
+# define CHR_MAX 0xfffffffe
+# else /* !__MACH__ */
+# if !defined(SIZEOF_WCHAR_T)
+# define CHRBITS 16
+# define CHR_MAX 0xfffe
+# else /* defined(SIZEOF_WCHAR_T) */
+# define CHRBITS SIZEOF_WCHAR_T
+# define CHR_MAX ((1 << CHRBITS) - 1)
+# endif /* !defined(SIZEOF_WCHAR_T) */
+# endif /* defined(__MACH__) */
+# endif /* defined(__WINDOWS__) */
+#else /* !wxUSE_UNICODE */