improve iswdigit macro to diagnose errors

this is analogous to commit 2ca55a93f2 for the macros in ctype.h.
11 years ago · d0040e239e
2 changed files with 2 additions and 2 deletions
--- a/include/wchar.h
+++ b/include/wchar.h
@ -175,7 +175,7 @@ wctype_t  wctype(const char *);

 #ifndef __cplusplus
 #undef iswdigit
-#define iswdigit(a) ((unsigned)(a)-'0' < 10)
+#define iswdigit(a) (0 ? iswdigit(a) : ((unsigned)(a)-'0') < 10)
 #endif
 #endif

--- a/include/wctype.h
+++ b/include/wctype.h
@ -45,7 +45,7 @@ wctype_t  wctype(const char *);

 #ifndef __cplusplus
 #undef iswdigit
-#define iswdigit(a) (((unsigned)(a)-L'0') < 10)
+#define iswdigit(a) (0 ? iswdigit(a) : ((unsigned)(a)-'0') < 10)
 #endif

 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \