Diff: tvmet/xpr/Eval.h

Revision:

1:cc2a9eb0bd55

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tvmet/xpr/Eval.h	Wed Oct 17 22:25:31 2012 +0000
@@ -0,0 +1,116 @@
+/*
+ * 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: Eval.h,v 1.13 2007-06-23 15:58:59 opetzold Exp $
+ */
+
+#ifndef TVMET_XPR_EVAL_H
+#define TVMET_XPR_EVAL_H
+
+namespace tvmet {
+
+
+/**
+ * \class XprEval Eval.h "tvmet/xpr/Eval.h"
+ * \brief evaluate the expression
+ *
+ * Since we can't overwrite the ? operator we have to write a wrapper
+ * for expression like return v1>v2 ? true : false
+ */
+template<class E1, class E2, class E3>
+class XprEval
+  : public TvmetBase< XprEval<E1, E2, E3> >
+{
+public:
+  typedef E1 						expr1_type;
+  typedef E2 						expr2_type;
+  typedef E3 						expr3_type;
+
+  typedef typename expr2_type::value_type 		value2_type;
+  typedef typename expr3_type::value_type 		value3_type;
+
+  typedef typename
+  PromoteTraits<value2_type, value3_type>::value_type 	value_type;
+
+public:
+  /** Complexity Counter */
+  enum {
+    ops_expr1 = E1::ops,
+    ops_expr2 = E2::ops,
+    ops_expr3 = E3::ops,
+    ops = ops_expr1	// only (e1 op e2) are evaluated
+  };
+
+private:
+  XprEval();
+  XprEval& operator=(const XprEval<expr1_type, expr2_type, expr3_type>&);
+
+public:
+  /** Constructor */
+  explicit XprEval(const expr1_type& e1, const expr2_type& e2, const expr3_type& e3)
+    : m_expr1(e1), m_expr2(e2), m_expr3(e3)
+  { }
+
+  /** Copy Constructor. Not explicit! */
+#if defined(TVMET_OPTIMIZE_XPR_MANUAL_CCTOR)
+  XprEval(const XprEval& rhs)
+    : m_expr1(rhs.m_expr1), m_expr2(rhs.m_expr2), m_expr3(rhs.m_expr3)
+  { }
+#endif
+
+public: //access
+  /** index operator for vectors. */
+  value_type operator()(std::size_t i) const {
+    return m_expr1(i) ? m_expr2(i) : m_expr3(i);
+  }
+
+  /** index operator for matrizes. */
+  value_type operator()(std::size_t i, std::size_t j) const {
+    return m_expr1(i, j) ? m_expr2(i, j) : m_expr3(i, j);
+  }
+
+public: // debugging Xpr parse tree
+  void print_xpr(std::ostream& os, std::size_t l=0) const {
+    os << IndentLevel(l++)
+       << "XprEval[" << ops << ", ("
+       << ops_expr1 << ", " << ops_expr2 << ", " << ops_expr3 << ")]<"
+       << std::endl;
+    m_expr1.print_xpr(os, l);
+    m_expr2.print_xpr(os, l);
+    m_expr3.print_xpr(os, l);
+    os << IndentLevel(--l)
+       << ">," << std::endl;
+  }
+
+private:
+  const expr1_type					m_expr1;
+  const expr2_type					m_expr2;
+  const expr3_type					m_expr3;
+};
+
+
+} // namespace tvmet
+
+#endif // TVMET_XPR_EVAL_H
+
+// Local Variables:
+// mode:C++
+// tab-width:8
+// End: