--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/liboctave/lo-traits.h	Thu Feb 12 02:49:14 2009 -0500
@@ -0,0 +1,80 @@
+/*
+
+Copyright (C) 2009 John W. Eaton
+
+This file is part of Octave.
+
+Octave 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 3 of the License, or (at your
+option) any later version.
+
+Octave 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.
+
+You should have received a copy of the GNU General Public License
+along with Octave; see the file COPYING.  If not, see
+<http://www.gnu.org/licenses/>.
+
+*/
+
+#if !defined (octave_liboctave_traits_h)
+#define octave_liboctave_traits_h 1
+
+template <bool cond, typename T1, typename T2>
+class if_then_else;
+
+template<typename T1, typename T2>
+class if_then_else<true, T1, T2>
+{
+public:
+
+  typedef T1 result;
+};
+
+template<typename T1, typename T2>
+class if_then_else<false, T1, T2>
+{
+public:
+
+  typedef T2 result;
+};
+
+template<typename T1>
+class is_class_type
+{
+private:
+
+  typedef char one;
+  typedef struct { char c[2]; } two;
+
+  // Classes can have pointers to members.
+  template<typename T2> static one is_class_type_test (int T2::*);
+
+  // Catch everything else.
+  template<typename T2> static two is_class_type_test (...);
+
+public:
+
+  enum { yes = sizeof (is_class_type_test<T1> (0)) == 1 };
+  enum { no = ! yes };
+};
+
+template<typename T>
+class ref_param
+{
+public:
+
+  typedef typename if_then_else<is_class_type<T>::no, T, T const&>::result type;
+};
+
+#endif
+
+/*
+;;; Local Variables: ***
+;;; mode: C ***
+;;; page-delimiter: "^/\\*" ***
+;;; End: ***
+*/