Big change in DiagonalMatrix and Geometry/Scaling:

* previous DiagonalMatrix expression is now DiagonalMatrixWrapper
* DiagonalMatrix class is now for storage
* add the DiagonalMatrixBase class to factorize code of the
  two previous classes
* remove Scaling class (it is now a global function)
* add UniformScaling helper class
  (don't use it directly, use the Scaling function)
* add the Scaling global function to simplify the creation
  of scaling objects
There is still a lot to do, in particular about DiagonalProduct for which
the goal is to get rid of the "if()" in the coeff() function. At least
it is not worse than before ! Also need to uptade the tutorial and add more doc.

1 files changed, 2 insertions, 0 deletions

diff --git a/Eigen/src/Core/NestByValue.h b/Eigen/src/Core/NestByValue.h
index da79315bf..dfe757447 100644
--- a/Eigen/src/Core/NestByValue.h
+++ b/Eigen/src/Core/NestByValue.h
@@ -97,6 +97,8 @@ template<typename ExpressionType> class NestByValue
     {
       m_expression.const_cast_derived().template writePacket<LoadMode>(index, x);
     }
+    
+    operator const ExpressionType&() const { return m_expression; }
 
   protected:
     const ExpressionType m_expression;