X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/6a590fd098f39b15d359a2320bcee03439f7d594..061c44b0289f52a5a895bbb26d1aca49e1488edb:/lib/sod.h

diff --git a/lib/sod.h b/lib/sod.h
index 9b9e611..af34d5d 100644
--- a/lib/sod.h
+++ b/lib/sod.h
@@ -9,19 +9,20 @@
  *
  * This file is part of the Sensble Object Design, an object system for C.
  *
- * SOD is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * The SOD Runtime Library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
  *
- * SOD is distributed in the hope that it will be useful,
+ * The SOD Runtime is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
+ * GNU Library General Public License for more details.
  *
- * You should have received a copy of the GNU General Public License
- * along with SOD; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * You should have received a copy of the GNU Library General Public
+ * License along with SOD; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
  */
 
 #ifndef SOD_H
@@ -52,7 +53,7 @@ struct sod_vtable {
  * 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,
@@ -123,6 +124,18 @@ struct sod_chain {
   ((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@ --- *
@@ -167,6 +180,19 @@ struct sod_chain {
 
 #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@ --- *