introduce ei_xxx_return_value and ei_xxx_impl for xxx in solve,kernel,impl

put them in a new internal 'misc' directory

Eigen/src/misc/Kernel.h

@@ -0,0 +1,71 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2009 Benoit Jacob <jacob.benoit.1@gmail.com>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, 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 of
+// the License, 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 Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef EIGEN_MISC_KERNEL_H
+#define EIGEN_MISC_KERNEL_H
+
+/** \class ei_kernel_return_value
+  *
+  */
+template<typename DecompositionType>
+struct ei_traits<ei_kernel_return_value<DecompositionType> >
+{
+  typedef typename DecompositionType::MatrixType MatrixType;
+  typedef Matrix<
+    typename MatrixType::Scalar,
+    MatrixType::ColsAtCompileTime, // the number of rows in the "kernel matrix"
+                                   // is the number of cols of the original matrix
+                                   // so that the product "matrix * kernel = zero" makes sense
+    Dynamic,                       // we don't know at compile-time the dimension of the kernel
+    MatrixType::Options,
+    MatrixType::MaxColsAtCompileTime, // see explanation for 2nd template parameter
+    MatrixType::MaxColsAtCompileTime // the kernel is a subspace of the domain space,
+                                     // whose dimension is the number of columns of the original matrix
+  > ReturnMatrixType;
+};
+
+template<typename _DecompositionType> struct ei_kernel_return_value
+ : public ReturnByValue<ei_kernel_return_value<_DecompositionType> >
+{
+  typedef _DecompositionType DecompositionType;
+  const DecompositionType& m_dec;
+  int m_rank, m_cols;
+
+  ei_kernel_return_value(const DecompositionType& dec)
+    : m_dec(dec),
+      m_rank(dec.rank()),
+      m_cols(m_rank==dec.cols() ? 1 : dec.cols() - m_rank)
+  {}
+
+  inline int rows() const { return m_dec.cols(); }
+  inline int cols() const { return m_cols; }
+
+  template<typename Dest> inline void evalTo(Dest& dst) const
+  {
+    static_cast<const ei_kernel_impl<DecompositionType, Dest> *>
+      (this)->evalTo(dst);
+  }
+};
+
+#endif // EIGEN_MISC_KERNEL_H