#endif
#ifdef HASATTRIBUTE
-# define PERL_UNUSED_DECL __attribute__((unused))
+# if defined(__GNUC__) && defined(__cplusplus)
+# define PERL_UNUSED_DECL
+# else
+# define PERL_UNUSED_DECL __attribute__((unused))
+# endif
#else
# define PERL_UNUSED_DECL
#endif