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Diffstat (limited to 'extern/Eigen3/Eigen/src/Core/NoAlias.h')
| -rw-r--r-- | extern/Eigen3/Eigen/src/Core/NoAlias.h | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/extern/Eigen3/Eigen/src/Core/NoAlias.h b/extern/Eigen3/Eigen/src/Core/NoAlias.h new file mode 100644 index 00000000000..da64affcf9a --- /dev/null +++ b/extern/Eigen3/Eigen/src/Core/NoAlias.h @@ -0,0 +1,136 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. +// +// Copyright (C) 2009 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_NOALIAS_H +#define EIGEN_NOALIAS_H + +/** \class NoAlias + * \ingroup Core_Module + * + * \brief Pseudo expression providing an operator = assuming no aliasing + * + * \param ExpressionType the type of the object on which to do the lazy assignment + * + * This class represents an expression with special assignment operators + * assuming no aliasing between the target expression and the source expression. + * More precisely it alloas to bypass the EvalBeforeAssignBit flag of the source expression. + * It is the return type of MatrixBase::noalias() + * and most of the time this is the only way it is used. + * + * \sa MatrixBase::noalias() + */ +template<typename ExpressionType, template <typename> class StorageBase> +class NoAlias +{ + typedef typename ExpressionType::Scalar Scalar; + public: + NoAlias(ExpressionType& expression) : m_expression(expression) {} + + /** Behaves like MatrixBase::lazyAssign(other) + * \sa MatrixBase::lazyAssign() */ + template<typename OtherDerived> + EIGEN_STRONG_INLINE ExpressionType& operator=(const StorageBase<OtherDerived>& other) + { return internal::assign_selector<ExpressionType,OtherDerived,false>::run(m_expression,other.derived()); } + + /** \sa MatrixBase::operator+= */ + template<typename OtherDerived> + EIGEN_STRONG_INLINE ExpressionType& operator+=(const StorageBase<OtherDerived>& other) + { + typedef SelfCwiseBinaryOp<internal::scalar_sum_op<Scalar>, ExpressionType, OtherDerived> SelfAdder; + SelfAdder tmp(m_expression); + typedef typename internal::nested<OtherDerived>::type OtherDerivedNested; + typedef typename internal::remove_all<OtherDerivedNested>::type _OtherDerivedNested; + internal::assign_selector<SelfAdder,_OtherDerivedNested,false>::run(tmp,OtherDerivedNested(other.derived())); + return m_expression; + } + + /** \sa MatrixBase::operator-= */ + template<typename OtherDerived> + EIGEN_STRONG_INLINE ExpressionType& operator-=(const StorageBase<OtherDerived>& other) + { + typedef SelfCwiseBinaryOp<internal::scalar_difference_op<Scalar>, ExpressionType, OtherDerived> SelfAdder; + SelfAdder tmp(m_expression); + typedef typename internal::nested<OtherDerived>::type OtherDerivedNested; + typedef typename internal::remove_all<OtherDerivedNested>::type _OtherDerivedNested; + internal::assign_selector<SelfAdder,_OtherDerivedNested,false>::run(tmp,OtherDerivedNested(other.derived())); + return m_expression; + } + +#ifndef EIGEN_PARSED_BY_DOXYGEN + template<typename ProductDerived, typename Lhs, typename Rhs> + EIGEN_STRONG_INLINE ExpressionType& operator+=(const ProductBase<ProductDerived, Lhs,Rhs>& other) + { other.derived().addTo(m_expression); return m_expression; } + + template<typename ProductDerived, typename Lhs, typename Rhs> + EIGEN_STRONG_INLINE ExpressionType& operator-=(const ProductBase<ProductDerived, Lhs,Rhs>& other) + { other.derived().subTo(m_expression); return m_expression; } + + template<typename Lhs, typename Rhs, int NestingFlags> + EIGEN_STRONG_INLINE ExpressionType& operator+=(const CoeffBasedProduct<Lhs,Rhs,NestingFlags>& other) + { return m_expression.derived() += CoeffBasedProduct<Lhs,Rhs,NestByRefBit>(other.lhs(), other.rhs()); } + + template<typename Lhs, typename Rhs, int NestingFlags> + EIGEN_STRONG_INLINE ExpressionType& operator-=(const CoeffBasedProduct<Lhs,Rhs,NestingFlags>& other) + { return m_expression.derived() -= CoeffBasedProduct<Lhs,Rhs,NestByRefBit>(other.lhs(), other.rhs()); } +#endif + + protected: + ExpressionType& m_expression; +}; + +/** \returns a pseudo expression of \c *this with an operator= assuming + * no aliasing between \c *this and the source expression. + * + * More precisely, noalias() allows to bypass the EvalBeforeAssignBit flag. + * Currently, even though several expressions may alias, only product + * expressions have this flag. Therefore, noalias() is only usefull when + * the source expression contains a matrix product. + * + * Here are some examples where noalias is usefull: + * \code + * D.noalias() = A * B; + * D.noalias() += A.transpose() * B; + * D.noalias() -= 2 * A * B.adjoint(); + * \endcode + * + * On the other hand the following example will lead to a \b wrong result: + * \code + * A.noalias() = A * B; + * \endcode + * because the result matrix A is also an operand of the matrix product. Therefore, + * there is no alternative than evaluating A * B in a temporary, that is the default + * behavior when you write: + * \code + * A = A * B; + * \endcode + * + * \sa class NoAlias + */ +template<typename Derived> +NoAlias<Derived,MatrixBase> MatrixBase<Derived>::noalias() +{ + return derived(); +} + +#endif // EIGEN_NOALIAS_H |