mruby/value.h: `MRB_TT_CPTR` is immediate with `MRB_NO_BOXING`.
The issue is reported by
@@ -177,7 +177,7 @@ struct RCptr {
#endif
#ifndef mrb_immediate_p
-#define mrb_immediate_p(o) (mrb_type(o) < MRB_TT_CPTR)
+#define mrb_immediate_p(o) (mrb_type(o) <= MRB_TT_CPTR)
#endif
#ifndef mrb_integer_p
#define mrb_integer_p(o) (mrb_type(o) == MRB_TT_INTEGER)
