+/**
+@defgroup ctfirvisitor CTF IR visitor
+@ingroup ctfir
+@brief CTF IR visitor.
+
+A CTF IR <strong><em>visitor</em></strong> is a function that you
+can use to visit the hierarchy of a
+\link ctfirtraceclass CTF IR trace class\endlink with
+bt_ctf_trace_visit() or of a
+\link ctfirstreamclass CTF IR stream class\endlink with
+bt_ctf_stream_class_visit().
+
+The traversal of the object's hierarchy is always done in a
+pre-order fashion.
+
+@sa ctfirstreamclass
+@sa ctfirtraceclass
+
+@file
+@brief CTF IR visitor types and functions.
+@sa ctfirvisitor
+
+@addtogroup ctfirvisitor
+@{
+*/
+
+/**
+@struct bt_ctf_object
+@brief A CTF IR object wrapper.
+
+This structure wraps both a CTF IR object and its type
+(see #bt_ctf_object_type). It is used in the visiting function.
+
+You can use the bt_ctf_object_get_type() and
+bt_ctf_object_get_object() accessors to get the type and wrapped
+CTF IR object of a CTF IR object wrapper.
+
+A CTF IR object wrapper has <strong>no reference count</strong>: do \em
+not use bt_put() or bt_get() on it.
+
+@sa ctfirvisitor
+*/