From: fred <fred>
Date: Tue, 26 Oct 1999 17:16:25 +0000 (+0000)
Subject: lilypond-1.3.0
X-Git-Tag: release/1.5.59~5761
X-Git-Url: https://git.donarmstrong.com/?a=commitdiff_plain;h=cf4da6cc3465e6e3130c44fd4b2cc43657afe0c2;p=lilypond.git

lilypond-1.3.0
---

diff --git a/lily/include/smobs.hh b/lily/include/smobs.hh
new file mode 100644
index 0000000000..a038db298e
--- /dev/null
+++ b/lily/include/smobs.hh
@@ -0,0 +1,50 @@
+/*   
+  smobs.hh -- declare smob related stuff.
+  
+  source file of the GNU LilyPond music typesetter
+  
+  (c) 1999 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+  
+ */
+
+#ifndef SMOBS_HH
+#define SMOBS_HH
+
+#include "lily-guile.hh"
+
+/**
+   A smob is a C++ class with static member functions to glue it with
+   Scheme. Every instance carries SELF_SCM_, a pointer to the Scheme
+   smob of itself.  Upon destruction, SELF_SCM_ is set to SCM_EOL.
+
+   smob_free() checks if SELF_SCM_ equals its argument, so we can also
+   use a smobbified object on the stack: the destruction will happen
+   before GC hits the object.
+
+   This is discouraged, though, because it causes memory leaks, and has
+   weird semantics.
+   
+
+*/
+
+#define DECLARE_SMOBS					\
+	SCM smobify_self ();					\
+	static SCM mark_smob (SCM);				\
+	static scm_sizet free_smob (SCM s);			\
+	static int print_smob (SCM s, SCM p, scm_print_state*);	\
+	static long smob_tag_;					\
+	static void init_smobs();				\
+	void unsmobify_self ();\
+        void do_smobify_self();\
+	SCM self_scm_;
+
+
+/**
+   Check if S is of the specified C++ class.
+ */
+#define SMOB_IS_TYPE_B(TYPE, S)  (SCM_NIMP((S)) && SCM_CAR((S)) == TYPE::smob_tag_)
+
+/// Cast S.  No checks are done.
+#define SMOB_TO_TYPE(TYPE, S)  ((TYPE*) SCM_CDR((S)))
+#endif /* SMOBS_HH */
+