CommaInitializer.h (5981B)
1 // This file is part of Eigen, a lightweight C++ template library 2 // for linear algebra. 3 // 4 // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr> 5 // Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com> 6 // 7 // This Source Code Form is subject to the terms of the Mozilla 8 // Public License v. 2.0. If a copy of the MPL was not distributed 9 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/. 10 11 #ifndef EIGEN_COMMAINITIALIZER_H 12 #define EIGEN_COMMAINITIALIZER_H 13 14 namespace Eigen { 15 16 /** \class CommaInitializer 17 * \ingroup Core_Module 18 * 19 * \brief Helper class used by the comma initializer operator 20 * 21 * This class is internally used to implement the comma initializer feature. It is 22 * the return type of MatrixBase::operator<<, and most of the time this is the only 23 * way it is used. 24 * 25 * \sa \blank \ref MatrixBaseCommaInitRef "MatrixBase::operator<<", CommaInitializer::finished() 26 */ 27 template<typename XprType> 28 struct CommaInitializer 29 { 30 typedef typename XprType::Scalar Scalar; 31 32 EIGEN_DEVICE_FUNC 33 inline CommaInitializer(XprType& xpr, const Scalar& s) 34 : m_xpr(xpr), m_row(0), m_col(1), m_currentBlockRows(1) 35 { 36 eigen_assert(m_xpr.rows() > 0 && m_xpr.cols() > 0 37 && "Cannot comma-initialize a 0x0 matrix (operator<<)"); 38 m_xpr.coeffRef(0,0) = s; 39 } 40 41 template<typename OtherDerived> 42 EIGEN_DEVICE_FUNC 43 inline CommaInitializer(XprType& xpr, const DenseBase<OtherDerived>& other) 44 : m_xpr(xpr), m_row(0), m_col(other.cols()), m_currentBlockRows(other.rows()) 45 { 46 eigen_assert(m_xpr.rows() >= other.rows() && m_xpr.cols() >= other.cols() 47 && "Cannot comma-initialize a 0x0 matrix (operator<<)"); 48 m_xpr.block(0, 0, other.rows(), other.cols()) = other; 49 } 50 51 /* Copy/Move constructor which transfers ownership. This is crucial in 52 * absence of return value optimization to avoid assertions during destruction. */ 53 // FIXME in C++11 mode this could be replaced by a proper RValue constructor 54 EIGEN_DEVICE_FUNC 55 inline CommaInitializer(const CommaInitializer& o) 56 : m_xpr(o.m_xpr), m_row(o.m_row), m_col(o.m_col), m_currentBlockRows(o.m_currentBlockRows) { 57 // Mark original object as finished. In absence of R-value references we need to const_cast: 58 const_cast<CommaInitializer&>(o).m_row = m_xpr.rows(); 59 const_cast<CommaInitializer&>(o).m_col = m_xpr.cols(); 60 const_cast<CommaInitializer&>(o).m_currentBlockRows = 0; 61 } 62 63 /* inserts a scalar value in the target matrix */ 64 EIGEN_DEVICE_FUNC 65 CommaInitializer& operator,(const Scalar& s) 66 { 67 if (m_col==m_xpr.cols()) 68 { 69 m_row+=m_currentBlockRows; 70 m_col = 0; 71 m_currentBlockRows = 1; 72 eigen_assert(m_row<m_xpr.rows() 73 && "Too many rows passed to comma initializer (operator<<)"); 74 } 75 eigen_assert(m_col<m_xpr.cols() 76 && "Too many coefficients passed to comma initializer (operator<<)"); 77 eigen_assert(m_currentBlockRows==1); 78 m_xpr.coeffRef(m_row, m_col++) = s; 79 return *this; 80 } 81 82 /* inserts a matrix expression in the target matrix */ 83 template<typename OtherDerived> 84 EIGEN_DEVICE_FUNC 85 CommaInitializer& operator,(const DenseBase<OtherDerived>& other) 86 { 87 if (m_col==m_xpr.cols() && (other.cols()!=0 || other.rows()!=m_currentBlockRows)) 88 { 89 m_row+=m_currentBlockRows; 90 m_col = 0; 91 m_currentBlockRows = other.rows(); 92 eigen_assert(m_row+m_currentBlockRows<=m_xpr.rows() 93 && "Too many rows passed to comma initializer (operator<<)"); 94 } 95 eigen_assert((m_col + other.cols() <= m_xpr.cols()) 96 && "Too many coefficients passed to comma initializer (operator<<)"); 97 eigen_assert(m_currentBlockRows==other.rows()); 98 m_xpr.template block<OtherDerived::RowsAtCompileTime, OtherDerived::ColsAtCompileTime> 99 (m_row, m_col, other.rows(), other.cols()) = other; 100 m_col += other.cols(); 101 return *this; 102 } 103 104 EIGEN_DEVICE_FUNC 105 inline ~CommaInitializer() 106 #if defined VERIFY_RAISES_ASSERT && (!defined EIGEN_NO_ASSERTION_CHECKING) && defined EIGEN_EXCEPTIONS 107 EIGEN_EXCEPTION_SPEC(Eigen::eigen_assert_exception) 108 #endif 109 { 110 finished(); 111 } 112 113 /** \returns the built matrix once all its coefficients have been set. 114 * Calling finished is 100% optional. Its purpose is to write expressions 115 * like this: 116 * \code 117 * quaternion.fromRotationMatrix((Matrix3f() << axis0, axis1, axis2).finished()); 118 * \endcode 119 */ 120 EIGEN_DEVICE_FUNC 121 inline XprType& finished() { 122 eigen_assert(((m_row+m_currentBlockRows) == m_xpr.rows() || m_xpr.cols() == 0) 123 && m_col == m_xpr.cols() 124 && "Too few coefficients passed to comma initializer (operator<<)"); 125 return m_xpr; 126 } 127 128 XprType& m_xpr; // target expression 129 Index m_row; // current row id 130 Index m_col; // current col id 131 Index m_currentBlockRows; // current block height 132 }; 133 134 /** \anchor MatrixBaseCommaInitRef 135 * Convenient operator to set the coefficients of a matrix. 136 * 137 * The coefficients must be provided in a row major order and exactly match 138 * the size of the matrix. Otherwise an assertion is raised. 139 * 140 * Example: \include MatrixBase_set.cpp 141 * Output: \verbinclude MatrixBase_set.out 142 * 143 * \note According the c++ standard, the argument expressions of this comma initializer are evaluated in arbitrary order. 144 * 145 * \sa CommaInitializer::finished(), class CommaInitializer 146 */ 147 template<typename Derived> 148 EIGEN_DEVICE_FUNC inline CommaInitializer<Derived> DenseBase<Derived>::operator<< (const Scalar& s) 149 { 150 return CommaInitializer<Derived>(*static_cast<Derived*>(this), s); 151 } 152 153 /** \sa operator<<(const Scalar&) */ 154 template<typename Derived> 155 template<typename OtherDerived> 156 EIGEN_DEVICE_FUNC inline CommaInitializer<Derived> 157 DenseBase<Derived>::operator<<(const DenseBase<OtherDerived>& other) 158 { 159 return CommaInitializer<Derived>(*static_cast<Derived *>(this), other); 160 } 161 162 } // end namespace Eigen 163 164 #endif // EIGEN_COMMAINITIALIZER_H