wip lib9o

1 files changed, 27 insertions, 0 deletions

diff --git a/lib9o/include/lib9o/lib9o.h b/lib9o/include/lib9o/lib9o.h
new file mode 100644
index 0000000..ed22293
--- /dev/null
+++ b/lib9o/include/lib9o/lib9o.h
@@ -0,0 +1,27 @@
+/* lib9o.h - A simple Go-ish object system built on GCC -fplan9-extensions
+ *
+ * Copyright (C) 2024  Luke T. Shumaker <lukeshu@lukeshu.com>
+ * SPDX-Licence-Identifier: AGPL-3.0-or-later
+ */
+
+#ifndef _LIB9O_H_
+#define _LIB9O_H_
+
+#include <assert.h> /* for assert() and static_assert() */
+#include <stddef.h> /* for offsetof() */
+
+#define MCALL(o, m, ...)                                     \
+	({                                                   \
+		assert(o);                                   \
+		(o)->vtable->m(o __VA_OPT__(,) __VA_ARGS__); \
+	})
+
+#define MSELF(obj_typ, iface_typ, iface_ptr)                                   \
+	({                                                                     \
+		static_assert(_Generic(iface_ptr, iface_typ *: 1, default: 0), \
+		              "typeof("#iface_ptr") != "#iface_typ);           \
+		assert(iface_ptr);                                             \
+		((obj_typ*)(((void*)iface_ptr)-offsetof(obj_typ,iface_typ)));  \
+	})
+
+#endif /* _LIB9O_H_ */