- eigen2 now fully enforces constness! found a way to achieve that

with minimal code duplication. There now are only two (2)
  const_cast remaining in the whole source code.
- eigen2 now fully allows copying a row-vector into a column-vector.
  added a unit-test for that.
- split unit tests, improve docs, various improvements.

test/map.cpp

@@ -0,0 +1,60 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra. Eigen itself is part of the KDE project.
+//
+// Copyright (C) 2006-2007 Benoit Jacob <jacob@math.jussieu.fr>
+//
+// Eigen 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 2 or (at your option) any later version.
+//
+// Eigen 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 Eigen; if not, write to the Free Software Foundation, Inc., 51
+// Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+//
+// As a special exception, if other files instantiate templates or use macros
+// or functions from this file, or you compile this file and link it
+// with other works to produce a work based on this file, this file does not
+// by itself cause the resulting work to be covered by the GNU General Public
+// License. This exception does not invalidate any other reasons why a work
+// based on this file might be covered by the GNU General Public License.
+
+#include "main.h"
+
+namespace Eigen {
+
+template<typename VectorType> void tmap(const VectorType& m)
+{
+  typedef typename VectorType::Scalar Scalar;
+  
+  int size = m.size();
+  
+  // test Map.h
+  Scalar* array1 = new Scalar[size];
+  Scalar* array2 = new Scalar[size];
+  VectorType::map(array1, size) = VectorType::random(size);
+  VectorType::map(array2, size) = VectorType::map(array1, size);
+  VectorType ma1 = VectorType::map(array1, size);
+  VectorType ma2 = VectorType::map(array2, size);
+  VERIFY_IS_APPROX(ma1, ma2);
+  VERIFY_IS_APPROX(ma1, VectorType(array2, size));
+  delete[] array1;
+  delete[] array2;
+}
+
+void EigenTest::testMap()
+{
+  for(int i = 0; i < m_repeat; i++) {
+    tmap(Matrix<float, 1, 1>());
+    tmap(Vector4d());
+    tmap(RowVector4f());
+    tmap(VectorXcf(8));
+    tmap(VectorXi(12));
+  }
+}
+
+} // namespace Eigen