text: // This file is part of Eigen, a lightweight C++ template library
  // for linear algebra.
  //
  // Copyright (C) 2008-2010 Gael Guennebaud <gael.guennebaud@inria.fr>
  //
  // 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_COREITERATORS_H
  #define EIGEN_COREITERATORS_H
  
  /* This file contains the respective InnerIterator definition of the expressions defined in Eigen/Core
   */
  
  /** \ingroup SparseCore_Module
    * \class InnerIterator
    * \brief An InnerIterator allows to loop over the element of a sparse (or dense) matrix or expression
    *
    * todo
    */
  
  // generic version for dense matrix and expressions
  template<typename Derived> class DenseBase<Derived>::InnerIterator
  {
    protected:
      typedef typename Derived::Scalar Scalar;
      typedef typename Derived::Index Index;
  
      enum { IsRowMajor = (Derived::Flags&RowMajorBit)==RowMajorBit };
    public:
      EIGEN_STRONG_INLINE InnerIterator(const Derived& expr, Index outer)
        : m_expression(expr), m_inner(0), m_outer(outer), m_end(expr.innerSize())
      {}
  
      EIGEN_STRONG_INLINE Scalar value() const
      {
        return (IsRowMajor) ? m_expression.coeff(m_outer, m_inner)
                            : m_expression.coeff(m_inner, m_outer);
      }
  
      EIGEN_STRONG_INLINE InnerIterator& operator++() { m_inner++; return *this; }
  
      EIGEN_STRONG_INLINE Index index() const { return m_inner; }
      inline Index row() const { return IsRowMajor ? m_outer : index(); }
      inline Index col() const { return IsRowMajor ? index() : m_outer; }
  
      EIGEN_STRONG_INLINE operator bool() const { return m_inner < m_end && m_inner>=0; }
  
    protected:
      const Derived& m_expression;
      Index m_inner;
      const Index m_outer;
      const Index m_end;
  };
  
  #endif // EIGEN_COREITERATORS_H
  