* these.
*/
struct sod_instance {
- struct sod_vtable *_vt; /* Pointer to (chain's) vtable */
+ const struct sod_vtable *_vt; /* Pointer to (chain's) vtable */
};
/* Information about a particular chain of superclasses. In each class,
* Arguments: @chead@ = nickname of target chain's head
* @obj@ = pointer to an instance chain
*
- * Returns: Pointer to target chain, as a @char *@.
+ * Returns: Pointer to target chain, as a @void *@.
*
* Use: Utility for implementing cross-chain upcasts. It's probably
* not that clever to use this macro directly; it's used to make
* the automatically-generated upcast macros more palatable.
*/
-#define SOD_XCHAIN(chead, obj) ((char *)(obj) + (obj)->_vt->_off_##chead)
+#define SOD_XCHAIN(chead, obj) \
+ ((void *)((char *)(obj) + (obj)->_vt->_off_##chead))
/* --- @SOD_OFFSETDIFF@ --- *
*
((struct cls##__ilayout *) \
((char *)(obj) - offsetof(struct cls##__ilayout, chead)))
+/* --- @SOD_CAR@ --- *
+ *
+ * Arguments: @...@ = a nonempty list of arguments
+ *
+ * Returns: The first argument only.
+ */
+
+#if __STDC_VERSION__ >= 199901
+# define SOD_CAR(...) SOD__CARx(__VA_LIST__, _)
+# define SOD__CARx(a, ...) a
+#endif
+
/*----- Utility macros ----------------------------------------------------*/
/* --- @SOD_CLASSOF@ --- *
#define SOD_CONVERT(cls, obj) ((cls *)sod_convert(cls##__class, (obj)))
+/* --- @SOD_DECL@ --- *
+ *
+ * Arguments: @cls_@ = a class type name
+ * @var_@ = a variable name
+ *
+ * Use: Declare @var_@ as a pointer to an initialized instance of
+ * @cls_@ with automatic lifetime.
+ */
+
+#define SOD_DECL(cls_, var_) \
+ struct cls_##__ilayout var_##__layout; \
+ cls_ *var_ = cls_##__class->cls.init(&var_##__layout)
+
/*----- Functions provided ------------------------------------------------*/
/* --- @sod_subclassp@ --- *