Changeset 95d54e6 for doc

Timestamp:

Jun 15, 2010, 1:05:52 AM (14 years ago)

Author:

David Benjamin <davidben@mit.edu>

Branches:

master, release-1.10, release-1.7, release-1.8, release-1.9

Children:

58ea109

Parents:

33b64f22

Message:

Document the glib function casts

File:

• doc/owl-window.txt (modified) (1 diff)

doc/owl-window.txt

@@ -174 +174 @@
   for the repaints to occur correctly. This is rather poor and should
   be refactored later.
+
+- The code fairly routinely does casts to add extra throw-away
+  parameters to functions. Most notably, casting functions of type
+
+      void do_something(void *obj)
+
+  to something of type
+
+      void do_something(void *obj, void *user_data)
+
+  (the latter is a GFunc) with the expectation that the user_data
+  argument is discarded. While calling with this cast is undefined by
+  the standard and depends on calling convention, glib uses it
+  internally /everywhere/ and much of glib and gobject API heavily
+  depends on it. As BarnOwl already depends on glib, we implicitly
+  assume this cast works.