NestByValue.h

00001 // This file is part of Eigen, a lightweight C++ template library
00002 // for linear algebra.
00003 //
00004 // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
00005 // Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
00006 //
00007 // This Source Code Form is subject to the terms of the Mozilla
00008 // Public License v. 2.0. If a copy of the MPL was not distributed
00009 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
00010 
00011 #ifndef EIGEN_NESTBYVALUE_H
00012 #define EIGEN_NESTBYVALUE_H
00013 
00014 namespace Eigen {
00015 
00016 /** \class NestByValue
00017   * \ingroup Core_Module
00018   *
00019   * \brief Expression which must be nested by value
00020   *
00021   * \param ExpressionType the type of the object of which we are requiring nesting-by-value
00022   *
00023   * This class is the return type of MatrixBase::nestByValue()
00024   * and most of the time this is the only way it is used.
00025   *
00026   * \sa MatrixBase::nestByValue()
00027   */
00028 
00029 namespace internal {
00030 template<typename ExpressionType>
00031 struct traits<NestByValue<ExpressionType> > : public traits<ExpressionType>
00032 {};
00033 }
00034 
00035 template<typename ExpressionType> class NestByValue
00036   : public internal::dense_xpr_base< NestByValue<ExpressionType> >::type
00037 {
00038   public:
00039 
00040     typedef typename internal::dense_xpr_base<NestByValue>::type Base;
00041     EIGEN_DENSE_PUBLIC_INTERFACE(NestByValue)
00042 
00043     inline NestByValue(const ExpressionType& matrix) : m_expression(matrix) {}
00044 
00045     inline Index rows() const { return m_expression.rows(); }
00046     inline Index cols() const { return m_expression.cols(); }
00047     inline Index outerStride() const { return m_expression.outerStride(); }
00048     inline Index innerStride() const { return m_expression.innerStride(); }
00049 
00050     inline const CoeffReturnType coeff(Index row, Index col) const
00051     {
00052       return m_expression.coeff(row, col);
00053     }
00054 
00055     inline Scalar& coeffRef(Index row, Index col)
00056     {
00057       return m_expression.const_cast_derived().coeffRef(row, col);
00058     }
00059 
00060     inline const CoeffReturnType coeff(Index index) const
00061     {
00062       return m_expression.coeff(index);
00063     }
00064 
00065     inline Scalar& coeffRef(Index index)
00066     {
00067       return m_expression.const_cast_derived().coeffRef(index);
00068     }
00069 
00070     template<int LoadMode>
00071     inline const PacketScalar packet(Index row, Index col) const
00072     {
00073       return m_expression.template packet<LoadMode>(row, col);
00074     }
00075 
00076     template<int LoadMode>
00077     inline void writePacket(Index row, Index col, const PacketScalar& x)
00078     {
00079       m_expression.const_cast_derived().template writePacket<LoadMode>(row, col, x);
00080     }
00081 
00082     template<int LoadMode>
00083     inline const PacketScalar packet(Index index) const
00084     {
00085       return m_expression.template packet<LoadMode>(index);
00086     }
00087 
00088     template<int LoadMode>
00089     inline void writePacket(Index index, const PacketScalar& x)
00090     {
00091       m_expression.const_cast_derived().template writePacket<LoadMode>(index, x);
00092     }
00093 
00094     operator const ExpressionType&() const { return m_expression; }
00095 
00096   protected:
00097     const ExpressionType m_expression;
00098 };
00099 
00100 /** \returns an expression of the temporary version of *this.
00101   */
00102 template<typename Derived>
00103 inline const NestByValue<Derived>
00104 DenseBase<Derived>::nestByValue() const
00105 {
00106   return NestByValue<Derived>(derived());
00107 }
00108 
00109 } // end namespace Eigen
00110 
00111 #endif // EIGEN_NESTBYVALUE_H