Make operator=(EigenBase<>) uses the new assignment mechanism and introduce a generic EigenBase to EigenBase assignment kind based on the previous evalTo mechanism.

Eigen/src/SparseCore/SparseAssign.h

@@ -167,8 +167,10 @@ struct storage_kind_to_shape<Sparse> {
 };
 
 struct Sparse2Sparse {};
+struct Sparse2Dense  {};
 
 template<> struct AssignmentKind<SparseShape,SparseShape> { typedef Sparse2Sparse Kind; };
+template<> struct AssignmentKind<DenseShape,SparseShape>  { typedef Sparse2Dense  Kind; };
 
 
 template<typename DstXprType, typename SrcXprType>
@@ -242,6 +244,24 @@ struct Assignment<DstXprType, SrcXprType, Functor, Sparse2Sparse, Scalar>
   }
 };
 
+// Sparse to Dense assignment
+template< typename DstXprType, typename SrcXprType, typename Functor, typename Scalar>
+struct Assignment<DstXprType, SrcXprType, Functor, Sparse2Dense, Scalar>
+{
+  static void run(DstXprType &dst, const SrcXprType &src, const internal::assign_op<typename DstXprType::Scalar> &/*func*/)
+  {
+    eigen_assert(dst.rows() == src.rows() && dst.cols() == src.cols());
+    typedef typename SrcXprType::Index Index;
+    
+    dst.setZero();
+    typename internal::evaluator<SrcXprType>::type srcEval(src);
+    typename internal::evaluator<DstXprType>::type dstEval(dst);
+    for (Index j=0; j<src.outerSize(); ++j)
+      for (typename internal::evaluator<SrcXprType>::InnerIterator i(srcEval,j); i; ++i)
+        dstEval.coeffRef(i.row(),i.col()) = i.value();
+  }
+};
+
 } // end namespace internal
 
 #endif // EIGEN_TEST_EVALUATORS

Eigen/src/SparseCore/SparseBlock.h

@@ -67,7 +67,7 @@ public:
     Index nonZeros() const
     {
 #ifndef EIGEN_TEST_EVALUATORS
-      typedef typename internal::evaluator<XprType>::type EvaluatorType;
+      Index nnz = 0;
       Index end = m_outerStart + m_outerSize.value();
       for(int j=m_outerStart; j<end; ++j)
         for(typename XprType::InnerIterator it(m_matrix, j); it; ++it)
@@ -641,7 +641,7 @@ public:
 template<typename ArgType, int BlockRows, int BlockCols, int InnerPanel>
 class unary_evaluator<Block<ArgType,BlockRows,BlockCols,InnerPanel>, IteratorBased>::OuterVectorInnerIterator
 {
-  const XprType& m_block;
+  const unary_evaluator& m_eval;
   Index m_outerPos;
   Index m_innerIndex;
   Scalar m_value;
@@ -649,10 +649,10 @@ class unary_evaluator<Block<ArgType,BlockRows,BlockCols,InnerPanel>, IteratorBas
 public:
 
   EIGEN_STRONG_INLINE OuterVectorInnerIterator(const unary_evaluator& aEval, Index outer)
-    : m_block(aEval.m_block),
-      m_outerPos( (IsRowMajor ? aEval.startCol() : aEval.startRow()) - 1), // -1 so that operator++ finds the first non-zero entry
-      m_innerIndex(IsRowMajor ? aEval.startRow() : aEval.startCol()),
-      m_end(IsRowMajor ? aEval.startCol()+aEval.blockCols() : aEval.startRow()+aEval.blockRows())
+    : m_eval(aEval),
+      m_outerPos( (IsRowMajor ? aEval.m_block.startCol() : aEval.m_block.startRow()) - 1), // -1 so that operator++ finds the first non-zero entry
+      m_innerIndex(IsRowMajor ? aEval.m_block.startRow() : aEval.m_block.startCol()),
+      m_end(IsRowMajor ? aEval.m_block.startCol()+aEval.m_block.blockCols() : aEval.m_block.startRow()+aEval.m_block.blockRows())
   {
     EIGEN_UNUSED_VARIABLE(outer);
     eigen_assert(outer==0);
@@ -660,7 +660,7 @@ public:
     ++(*this);
   }
   
-  inline Index index()  const { return m_outerPos - (IsRowMajor ? m_block.startCol() : m_block.startRow()); }
+  inline Index index()  const { return m_outerPos - (IsRowMajor ? m_eval.m_block.startCol() : m_eval.m_block.startRow()); }
   inline Index outer()  const { return 0; }
   inline Index row()    const { return IsRowMajor ? 0 : index(); }
   inline Index col()    const { return IsRowMajor ? index() : 0; }
@@ -673,7 +673,7 @@ public:
     while(m_outerPos<m_end)
     {
       m_outerPos++;
-      typename XprType::InnerIterator it(m_block.m_matrix, m_outerPos);
+      EvalIterator it(m_eval.m_argImpl, m_outerPos);
       // search for the key m_innerIndex in the current outer-vector
       while(it && it.index() < m_innerIndex) ++it;
       if(it && it.index()==m_innerIndex)

Eigen/src/SparseCore/SparseMatrixBase.h

@@ -337,6 +337,7 @@ template<typename Derived> class SparseMatrixBase : public EigenBase<Derived>
     Block<Derived,Dynamic,Dynamic,true> innerVectors(Index outerStart, Index outerSize);
     const Block<const Derived,Dynamic,Dynamic,true> innerVectors(Index outerStart, Index outerSize) const;
 
+#ifndef EIGEN_TEST_EVALUATORS
     /** \internal use operator= */
     template<typename DenseDerived>
     void evalTo(MatrixBase<DenseDerived>& dst) const
@@ -346,6 +347,7 @@ template<typename Derived> class SparseMatrixBase : public EigenBase<Derived>
         for (typename Derived::InnerIterator i(derived(),j); i; ++i)
           dst.coeffRef(i.row(),i.col()) = i.value();
     }
+#endif
 
     Matrix<Scalar,RowsAtCompileTime,ColsAtCompileTime> toDense() const
     {