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
14namespace 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 */
27template<typename XprType>
28struct 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 m_xpr.coeffRef(0,0) = s;
37 }
38
39 template<typename OtherDerived>
40 EIGEN_DEVICE_FUNC
41 inline CommaInitializer(XprType& xpr, const DenseBase<OtherDerived>& other)
42 : m_xpr(xpr), m_row(0), m_col(other.cols()), m_currentBlockRows(other.rows())
43 {
44 m_xpr.block(0, 0, other.rows(), other.cols()) = other;
45 }
46
47 /* Copy/Move constructor which transfers ownership. This is crucial in
48 * absence of return value optimization to avoid assertions during destruction. */
49 // FIXME in C++11 mode this could be replaced by a proper RValue constructor
50 EIGEN_DEVICE_FUNC
51 inline CommaInitializer(const CommaInitializer& o)
52 : m_xpr(o.m_xpr), m_row(o.m_row), m_col(o.m_col), m_currentBlockRows(o.m_currentBlockRows) {
53 // Mark original object as finished. In absence of R-value references we need to const_cast:
54 const_cast<CommaInitializer&>(o).m_row = m_xpr.rows();
55 const_cast<CommaInitializer&>(o).m_col = m_xpr.cols();
56 const_cast<CommaInitializer&>(o).m_currentBlockRows = 0;
57 }
58
59 /* inserts a scalar value in the target matrix */
60 EIGEN_DEVICE_FUNC
61 CommaInitializer& operator,(const Scalar& s)
62 {
63 if (m_col==m_xpr.cols())
64 {
65 m_row+=m_currentBlockRows;
66 m_col = 0;
67 m_currentBlockRows = 1;
68 eigen_assert(m_row<m_xpr.rows()
69 && "Too many rows passed to comma initializer (operator<<)");
70 }
71 eigen_assert(m_col<m_xpr.cols()
72 && "Too many coefficients passed to comma initializer (operator<<)");
73 eigen_assert(m_currentBlockRows==1);
74 m_xpr.coeffRef(m_row, m_col++) = s;
75 return *this;
76 }
77
78 /* inserts a matrix expression in the target matrix */
79 template<typename OtherDerived>
80 EIGEN_DEVICE_FUNC
81 CommaInitializer& operator,(const DenseBase<OtherDerived>& other)
82 {
83 if (m_col==m_xpr.cols() && (other.cols()!=0 || other.rows()!=m_currentBlockRows))
84 {
85 m_row+=m_currentBlockRows;
86 m_col = 0;
87 m_currentBlockRows = other.rows();
88 eigen_assert(m_row+m_currentBlockRows<=m_xpr.rows()
89 && "Too many rows passed to comma initializer (operator<<)");
90 }
91 eigen_assert((m_col + other.cols() <= m_xpr.cols())
92 && "Too many coefficients passed to comma initializer (operator<<)");
93 eigen_assert(m_currentBlockRows==other.rows());
94 m_xpr.template block<OtherDerived::RowsAtCompileTime, OtherDerived::ColsAtCompileTime>
95 (m_row, m_col, other.rows(), other.cols()) = other;
96 m_col += other.cols();
97 return *this;
98 }
99
100 EIGEN_DEVICE_FUNC
101 inline ~CommaInitializer()
102#if defined VERIFY_RAISES_ASSERT && (!defined EIGEN_NO_ASSERTION_CHECKING) && defined EIGEN_EXCEPTIONS
103 EIGEN_EXCEPTION_SPEC(Eigen::eigen_assert_exception)
104#endif
105 {
106 finished();
107 }
108
109 /** \returns the built matrix once all its coefficients have been set.
110 * Calling finished is 100% optional. Its purpose is to write expressions
111 * like this:
112 * \code
113 * quaternion.fromRotationMatrix((Matrix3f() << axis0, axis1, axis2).finished());
114 * \endcode
115 */
116 EIGEN_DEVICE_FUNC
117 inline XprType& finished() {
118 eigen_assert(((m_row+m_currentBlockRows) == m_xpr.rows() || m_xpr.cols() == 0)
119 && m_col == m_xpr.cols()
120 && "Too few coefficients passed to comma initializer (operator<<)");
121 return m_xpr;
122 }
123
124 XprType& m_xpr; // target expression
125 Index m_row; // current row id
126 Index m_col; // current col id
127 Index m_currentBlockRows; // current block height
128};
129
130/** \anchor MatrixBaseCommaInitRef
131 * Convenient operator to set the coefficients of a matrix.
132 *
133 * The coefficients must be provided in a row major order and exactly match
134 * the size of the matrix. Otherwise an assertion is raised.
135 *
136 * Example: \include MatrixBase_set.cpp
137 * Output: \verbinclude MatrixBase_set.out
138 *
139 * \note According the c++ standard, the argument expressions of this comma initializer are evaluated in arbitrary order.
140 *
141 * \sa CommaInitializer::finished(), class CommaInitializer
142 */
143template<typename Derived>
144inline CommaInitializer<Derived> DenseBase<Derived>::operator<< (const Scalar& s)
145{
146 return CommaInitializer<Derived>(*static_cast<Derived*>(this), s);
147}
148
149/** \sa operator<<(const Scalar&) */
150template<typename Derived>
151template<typename OtherDerived>
152inline CommaInitializer<Derived>
153DenseBase<Derived>::operator<<(const DenseBase<OtherDerived>& other)
154{
155 return CommaInitializer<Derived>(*static_cast<Derived *>(this), other);
156}
157
158} // end namespace Eigen
159
160#endif // EIGEN_COMMAINITIALIZER_H
161