Diff: tvmet/xpr/Identity.h

Revision:

1:cc2a9eb0bd55

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tvmet/xpr/Identity.h	Wed Oct 17 22:25:31 2012 +0000
@@ -0,0 +1,68 @@
+/*
+ * $Id: Identity.h,v 1.4 2006-11-21 18:43:09 opetzold Exp $
+ */
+
+#ifndef TVMET_XPR_IDENTITY_H
+#define TVMET_XPR_IDENTITY_H
+
+
+namespace tvmet {
+
+
+/**
+ * \class XprIdentity Identity.h "tvmet/xpr/Identity.h"
+ * \brief Expression for the identity matrix.
+ *
+ * This expression doesn't hold any other expression, it
+ * simply returns 1 or 0 depends where the row and column
+ * element excess is done.
+ *
+ * \since release 1.6.0
+ * \sa identity
+ */
+template<class T, std::size_t Rows, std::size_t Cols>
+struct XprIdentity
+  : public TvmetBase< XprIdentity<T, Rows, Cols> >
+{
+  XprIdentity& operator=(const XprIdentity&);
+
+public:
+  typedef T				value_type;
+
+public:
+  /** Complexity counter. */
+  enum {
+    ops_assign = Rows * Cols,
+    ops        = ops_assign
+  };
+
+public:
+  /** access by index. */
+  value_type operator()(std::size_t i, std::size_t j) const {
+    return i==j ? 1 : 0;
+  }
+
+public: // debugging Xpr parse tree
+  void print_xpr(std::ostream& os, std::size_t l=0) const {
+    os << IndentLevel(l++)
+       << "XprIdentity[O="<< ops << ")]<"
+       << std::endl;
+    os << IndentLevel(l)
+       << typeid(T).name() << ","
+       << "R=" << Rows << ", C=" << Cols << std::endl;
+    os << IndentLevel(--l) << ">"
+       << ((l != 0) ? "," : "") << std::endl;
+  }
+};
+
+
+} // namespace tvmet
+
+
+#endif // TVMET_XPR_IDENTITY_H
+
+
+// Local Variables:
+// mode:C++
+// tab-width:8
+// End: