Diff: tvmet/xpr/Null.h

Revision:

15:9c5aaeda36dc

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tvmet/xpr/Null.h	Sat Apr 06 20:57:54 2013 +0000
@@ -0,0 +1,69 @@
+/*
+ * Tiny Vector Matrix Library
+ * Dense Vector Matrix Libary of Tiny size using Expression Templates
+ *
+ * Copyright (C) 2001 - 2007 Olaf Petzold <opetzold@users.sourceforge.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * $Id: Null.h,v 1.11 2007-06-23 15:59:00 opetzold Exp $
+ */
+
+#ifndef TVMET_XPR_NULL_H
+#define TVMET_XPR_NULL_H
+
+namespace tvmet {
+
+
+/**
+ * \class XprNull Null.h "tvmet/xpr/Null.h"
+ * \brief Null object design pattern
+ */
+class XprNull
+  : public TvmetBase< XprNull >
+{
+  XprNull& operator=(const XprNull&);
+
+public:
+  explicit XprNull() { }
+
+public: // debugging Xpr parse tree
+  void print_xpr(std::ostream& os, std::size_t l=0) const {
+    os << IndentLevel(l) << "XprNull[O=0]" << std::endl;
+  }
+};
+
+
+#define TVMET_BINARY_OPERATOR(OP)                               \
+template< class T >                                        \
+inline                                             \
+T operator OP (const T& lhs, XprNull) { return lhs; }
+
+TVMET_BINARY_OPERATOR(+)
+TVMET_BINARY_OPERATOR(-)
+TVMET_BINARY_OPERATOR(*)
+TVMET_BINARY_OPERATOR(/)
+
+#undef TVMET_BINARY_OPERATOR
+
+
+} // namespace tvmet
+
+#endif // TVMET_XPR_NULL_H
+
+// Local Variables:
+// mode:C++
+// tab-width:8
+// End: