Update Eigen to the latest stable release, 3.2.2

./Eigen/src/Core/util/NonMPL2.h is left untouched, so that
usage of non MPL2 code is disabled.

Change-Id: I86fc9257b3c30d0ca15b268d4ef07bf038bba7ca
diff --git a/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h b/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
index 84fd72f..532896c 100644
--- a/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
+++ b/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
@@ -3,153 +3,240 @@
 //
 // Copyright (C) 2011 Kolja Brix <brix@igpm.rwth-aachen.de>
 // Copyright (C) 2011 Andreas Platen <andiplaten@gmx.de>
+// Copyright (C) 2012 Chen-Pang He <jdh8@ms63.hinet.net>
 //
 // This Source Code Form is subject to the terms of the Mozilla
 // Public License v. 2.0. If a copy of the MPL was not distributed
 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-
 #ifndef KRONECKER_TENSOR_PRODUCT_H
 #define KRONECKER_TENSOR_PRODUCT_H
 
-
 namespace Eigen { 
 
-namespace internal {
+template<typename Scalar, int Options, typename Index> class SparseMatrix;
 
 /*!
- * Kronecker tensor product helper function for dense matrices
+ * \brief Kronecker tensor product helper class for dense matrices
  *
- * \param A   Dense matrix A
- * \param B   Dense matrix B
- * \param AB_ Kronecker tensor product of A and B
+ * This class is the return value of kroneckerProduct(MatrixBase,
+ * MatrixBase). Use the function rather than construct this class
+ * directly to avoid specifying template prarameters.
+ *
+ * \tparam Lhs  Type of the left-hand side, a matrix expression.
+ * \tparam Rhs  Type of the rignt-hand side, a matrix expression.
  */
-template<typename Derived_A, typename Derived_B, typename Derived_AB>
-void kroneckerProduct_full(const Derived_A& A, const Derived_B& B, Derived_AB & AB)
+template<typename Lhs, typename Rhs>
+class KroneckerProduct : public ReturnByValue<KroneckerProduct<Lhs,Rhs> >
 {
-  const unsigned int Ar = A.rows(),
-                     Ac = A.cols(),
-                     Br = B.rows(),
-                     Bc = B.cols();
-  for (unsigned int i=0; i<Ar; ++i)
-    for (unsigned int j=0; j<Ac; ++j)
-      AB.block(i*Br,j*Bc,Br,Bc) = A(i,j)*B;
+  private:
+    typedef ReturnByValue<KroneckerProduct> Base;
+    typedef typename Base::Scalar Scalar;
+    typedef typename Base::Index Index;
+
+  public:
+    /*! \brief Constructor. */
+    KroneckerProduct(const Lhs& A, const Rhs& B)
+      : m_A(A), m_B(B)
+    {}
+
+    /*! \brief Evaluate the Kronecker tensor product. */
+    template<typename Dest> void evalTo(Dest& dst) const;
+    
+    inline Index rows() const { return m_A.rows() * m_B.rows(); }
+    inline Index cols() const { return m_A.cols() * m_B.cols(); }
+
+    Scalar coeff(Index row, Index col) const
+    {
+      return m_A.coeff(row / m_B.rows(), col / m_B.cols()) *
+             m_B.coeff(row % m_B.rows(), col % m_B.cols());
+    }
+
+    Scalar coeff(Index i) const
+    {
+      EIGEN_STATIC_ASSERT_VECTOR_ONLY(KroneckerProduct);
+      return m_A.coeff(i / m_A.size()) * m_B.coeff(i % m_A.size());
+    }
+
+  private:
+    typename Lhs::Nested m_A;
+    typename Rhs::Nested m_B;
+};
+
+/*!
+ * \brief Kronecker tensor product helper class for sparse matrices
+ *
+ * If at least one of the operands is a sparse matrix expression,
+ * then this class is returned and evaluates into a sparse matrix.
+ *
+ * This class is the return value of kroneckerProduct(EigenBase,
+ * EigenBase). Use the function rather than construct this class
+ * directly to avoid specifying template prarameters.
+ *
+ * \tparam Lhs  Type of the left-hand side, a matrix expression.
+ * \tparam Rhs  Type of the rignt-hand side, a matrix expression.
+ */
+template<typename Lhs, typename Rhs>
+class KroneckerProductSparse : public EigenBase<KroneckerProductSparse<Lhs,Rhs> >
+{
+  private:
+    typedef typename internal::traits<KroneckerProductSparse>::Index Index;
+
+  public:
+    /*! \brief Constructor. */
+    KroneckerProductSparse(const Lhs& A, const Rhs& B)
+      : m_A(A), m_B(B)
+    {}
+
+    /*! \brief Evaluate the Kronecker tensor product. */
+    template<typename Dest> void evalTo(Dest& dst) const;
+    
+    inline Index rows() const { return m_A.rows() * m_B.rows(); }
+    inline Index cols() const { return m_A.cols() * m_B.cols(); }
+
+    template<typename Scalar, int Options, typename Index>
+    operator SparseMatrix<Scalar, Options, Index>()
+    {
+      SparseMatrix<Scalar, Options, Index> result;
+      evalTo(result.derived());
+      return result;
+    }
+
+  private:
+    typename Lhs::Nested m_A;
+    typename Rhs::Nested m_B;
+};
+
+template<typename Lhs, typename Rhs>
+template<typename Dest>
+void KroneckerProduct<Lhs,Rhs>::evalTo(Dest& dst) const
+{
+  const int BlockRows = Rhs::RowsAtCompileTime,
+            BlockCols = Rhs::ColsAtCompileTime;
+  const Index Br = m_B.rows(),
+              Bc = m_B.cols();
+  for (Index i=0; i < m_A.rows(); ++i)
+    for (Index j=0; j < m_A.cols(); ++j)
+      Block<Dest,BlockRows,BlockCols>(dst,i*Br,j*Bc,Br,Bc) = m_A.coeff(i,j) * m_B;
 }
 
-
-/*!
- * Kronecker tensor product helper function for matrices, where at least one is sparse
- *
- * \param A   Matrix A
- * \param B   Matrix B
- * \param AB_ Kronecker tensor product of A and B
- */
-template<typename Derived_A, typename Derived_B, typename Derived_AB>
-void kroneckerProduct_sparse(const Derived_A &A, const Derived_B &B, Derived_AB &AB)
+template<typename Lhs, typename Rhs>
+template<typename Dest>
+void KroneckerProductSparse<Lhs,Rhs>::evalTo(Dest& dst) const
 {
-  const unsigned int Ar = A.rows(),
-                     Ac = A.cols(),
-                     Br = B.rows(),
-                     Bc = B.cols();
-  AB.resize(Ar*Br,Ac*Bc);
-  AB.resizeNonZeros(0);
-  AB.reserve(A.nonZeros()*B.nonZeros());
+  const Index Br = m_B.rows(),
+              Bc = m_B.cols();
+  dst.resize(rows(),cols());
+  dst.resizeNonZeros(0);
+  dst.reserve(m_A.nonZeros() * m_B.nonZeros());
 
-  for (int kA=0; kA<A.outerSize(); ++kA)
+  for (Index kA=0; kA < m_A.outerSize(); ++kA)
   {
-    for (int kB=0; kB<B.outerSize(); ++kB)
+    for (Index kB=0; kB < m_B.outerSize(); ++kB)
     {
-      for (typename Derived_A::InnerIterator itA(A,kA); itA; ++itA)
+      for (typename Lhs::InnerIterator itA(m_A,kA); itA; ++itA)
       {
-        for (typename Derived_B::InnerIterator itB(B,kB); itB; ++itB)
+        for (typename Rhs::InnerIterator itB(m_B,kB); itB; ++itB)
         {
-          const unsigned int iA = itA.row(),
-                             jA = itA.col(),
-                             iB = itB.row(),
-                             jB = itB.col(),
-                             i  = iA*Br + iB,
-                             j  = jA*Bc + jB;
-          AB.insert(i,j) = itA.value() * itB.value();
+          const Index i = itA.row() * Br + itB.row(),
+                      j = itA.col() * Bc + itB.col();
+          dst.insert(i,j) = itA.value() * itB.value();
         }
       }
     }
   }
 }
 
+namespace internal {
+
+template<typename _Lhs, typename _Rhs>
+struct traits<KroneckerProduct<_Lhs,_Rhs> >
+{
+  typedef typename remove_all<_Lhs>::type Lhs;
+  typedef typename remove_all<_Rhs>::type Rhs;
+  typedef typename scalar_product_traits<typename Lhs::Scalar, typename Rhs::Scalar>::ReturnType Scalar;
+
+  enum {
+    Rows = size_at_compile_time<traits<Lhs>::RowsAtCompileTime, traits<Rhs>::RowsAtCompileTime>::ret,
+    Cols = size_at_compile_time<traits<Lhs>::ColsAtCompileTime, traits<Rhs>::ColsAtCompileTime>::ret,
+    MaxRows = size_at_compile_time<traits<Lhs>::MaxRowsAtCompileTime, traits<Rhs>::MaxRowsAtCompileTime>::ret,
+    MaxCols = size_at_compile_time<traits<Lhs>::MaxColsAtCompileTime, traits<Rhs>::MaxColsAtCompileTime>::ret,
+    CoeffReadCost = Lhs::CoeffReadCost + Rhs::CoeffReadCost + NumTraits<Scalar>::MulCost
+  };
+
+  typedef Matrix<Scalar,Rows,Cols> ReturnType;
+};
+
+template<typename _Lhs, typename _Rhs>
+struct traits<KroneckerProductSparse<_Lhs,_Rhs> >
+{
+  typedef MatrixXpr XprKind;
+  typedef typename remove_all<_Lhs>::type Lhs;
+  typedef typename remove_all<_Rhs>::type Rhs;
+  typedef typename scalar_product_traits<typename Lhs::Scalar, typename Rhs::Scalar>::ReturnType Scalar;
+  typedef typename promote_storage_type<typename traits<Lhs>::StorageKind, typename traits<Rhs>::StorageKind>::ret StorageKind;
+  typedef typename promote_index_type<typename Lhs::Index, typename Rhs::Index>::type Index;
+
+  enum {
+    LhsFlags = Lhs::Flags,
+    RhsFlags = Rhs::Flags,
+
+    RowsAtCompileTime = size_at_compile_time<traits<Lhs>::RowsAtCompileTime, traits<Rhs>::RowsAtCompileTime>::ret,
+    ColsAtCompileTime = size_at_compile_time<traits<Lhs>::ColsAtCompileTime, traits<Rhs>::ColsAtCompileTime>::ret,
+    MaxRowsAtCompileTime = size_at_compile_time<traits<Lhs>::MaxRowsAtCompileTime, traits<Rhs>::MaxRowsAtCompileTime>::ret,
+    MaxColsAtCompileTime = size_at_compile_time<traits<Lhs>::MaxColsAtCompileTime, traits<Rhs>::MaxColsAtCompileTime>::ret,
+
+    EvalToRowMajor = (LhsFlags & RhsFlags & RowMajorBit),
+    RemovedBits = ~(EvalToRowMajor ? 0 : RowMajorBit),
+
+    Flags = ((LhsFlags | RhsFlags) & HereditaryBits & RemovedBits)
+          | EvalBeforeNestingBit | EvalBeforeAssigningBit,
+    CoeffReadCost = Dynamic
+  };
+};
+
 } // end namespace internal
 
-
-
 /*!
+ * \ingroup KroneckerProduct_Module
+ *
  * Computes Kronecker tensor product of two dense matrices
  *
- * \param a  Dense matrix a
- * \param b  Dense matrix b
- * \param c  Kronecker tensor product of a and b
- */
-template<typename A,typename B,typename CScalar,int CRows,int CCols, int COptions, int CMaxRows, int CMaxCols>
-void kroneckerProduct(const MatrixBase<A>& a, const MatrixBase<B>& b, Matrix<CScalar,CRows,CCols,COptions,CMaxRows,CMaxCols>& c)
-{
-  c.resize(a.rows()*b.rows(),a.cols()*b.cols());
-  internal::kroneckerProduct_full(a.derived(), b.derived(), c);
-}
-
-/*!
- * Computes Kronecker tensor product of two dense matrices
- *
- * Remark: this function uses the const cast hack and has been
- *         implemented to make the function call possible, where the
- *         output matrix is a submatrix, e.g.
- *           kroneckerProduct(A,B,AB.block(2,5,6,6));
+ * \warning If you want to replace a matrix by its Kronecker product
+ *          with some matrix, do \b NOT do this:
+ * \code
+ * A = kroneckerProduct(A,B); // bug!!! caused by aliasing effect
+ * \endcode
+ * instead, use eval() to work around this:
+ * \code
+ * A = kroneckerProduct(A,B).eval();
+ * \endcode
  *
  * \param a  Dense matrix a
  * \param b  Dense matrix b
- * \param c  Kronecker tensor product of a and b
+ * \return   Kronecker tensor product of a and b
  */
-template<typename A,typename B,typename C>
-void kroneckerProduct(const MatrixBase<A>& a, const MatrixBase<B>& b, MatrixBase<C> const & c_)
+template<typename A, typename B>
+KroneckerProduct<A,B> kroneckerProduct(const MatrixBase<A>& a, const MatrixBase<B>& b)
 {
-  MatrixBase<C>& c = const_cast<MatrixBase<C>& >(c_);
-  internal::kroneckerProduct_full(a.derived(), b.derived(), c.derived());
+  return KroneckerProduct<A, B>(a.derived(), b.derived());
 }
 
 /*!
- * Computes Kronecker tensor product of a dense and a sparse matrix
+ * \ingroup KroneckerProduct_Module
  *
- * \param a  Dense matrix a
- * \param b  Sparse matrix b
- * \param c  Kronecker tensor product of a and b
- */
-template<typename A,typename B,typename C>
-void kroneckerProduct(const MatrixBase<A>& a, const SparseMatrixBase<B>& b, SparseMatrixBase<C>& c)
-{
-  internal::kroneckerProduct_sparse(a.derived(), b.derived(), c.derived());
-}
-
-/*!
- * Computes Kronecker tensor product of a sparse and a dense matrix
+ * Computes Kronecker tensor product of two matrices, at least one of
+ * which is sparse
  *
- * \param a  Sparse matrix a
- * \param b  Dense matrix b
- * \param c  Kronecker tensor product of a and b
+ * \param a  Dense/sparse matrix a
+ * \param b  Dense/sparse matrix b
+ * \return   Kronecker tensor product of a and b, stored in a sparse
+ *           matrix
  */
-template<typename A,typename B,typename C>
-void kroneckerProduct(const SparseMatrixBase<A>& a, const MatrixBase<B>& b, SparseMatrixBase<C>& c)
+template<typename A, typename B>
+KroneckerProductSparse<A,B> kroneckerProduct(const EigenBase<A>& a, const EigenBase<B>& b)
 {
-  internal::kroneckerProduct_sparse(a.derived(), b.derived(), c.derived());
-}
-
-/*!
- * Computes Kronecker tensor product of two sparse matrices
- *
- * \param a  Sparse matrix a
- * \param b  Sparse matrix b
- * \param c  Kronecker tensor product of a and b
- */
-template<typename A,typename B,typename C>
-void kroneckerProduct(const SparseMatrixBase<A>& a, const SparseMatrixBase<B>& b, SparseMatrixBase<C>& c)
-{
-  internal::kroneckerProduct_sparse(a.derived(), b.derived(), c.derived());
+  return KroneckerProductSparse<A,B>(a.derived(), b.derived());
 }
 
 } // end namespace Eigen