1 | // This file is part of Eigen, a lightweight C++ template library
|
---|
2 | // for linear algebra.
|
---|
3 | //
|
---|
4 | // Copyright (C) 2009-2010 Gael Guennebaud <gael.guennebaud@inria.fr>
|
---|
5 | // Copyright (C) 2009-2010 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_RETURNBYVALUE_H
|
---|
12 | #define EIGEN_RETURNBYVALUE_H
|
---|
13 |
|
---|
14 | namespace Eigen {
|
---|
15 |
|
---|
16 | /** \class ReturnByValue
|
---|
17 | * \ingroup Core_Module
|
---|
18 | *
|
---|
19 | */
|
---|
20 |
|
---|
21 | namespace internal {
|
---|
22 |
|
---|
23 | template<typename Derived>
|
---|
24 | struct traits<ReturnByValue<Derived> >
|
---|
25 | : public traits<typename traits<Derived>::ReturnType>
|
---|
26 | {
|
---|
27 | enum {
|
---|
28 | // We're disabling the DirectAccess because e.g. the constructor of
|
---|
29 | // the Block-with-DirectAccess expression requires to have a coeffRef method.
|
---|
30 | // Also, we don't want to have to implement the stride stuff.
|
---|
31 | Flags = (traits<typename traits<Derived>::ReturnType>::Flags
|
---|
32 | | EvalBeforeNestingBit) & ~DirectAccessBit
|
---|
33 | };
|
---|
34 | };
|
---|
35 |
|
---|
36 | /* The ReturnByValue object doesn't even have a coeff() method.
|
---|
37 | * So the only way that nesting it in an expression can work, is by evaluating it into a plain matrix.
|
---|
38 | * So internal::nested always gives the plain return matrix type.
|
---|
39 | *
|
---|
40 | * FIXME: I don't understand why we need this specialization: isn't this taken care of by the EvalBeforeNestingBit ??
|
---|
41 | */
|
---|
42 | template<typename Derived,int n,typename PlainObject>
|
---|
43 | struct nested<ReturnByValue<Derived>, n, PlainObject>
|
---|
44 | {
|
---|
45 | typedef typename traits<Derived>::ReturnType type;
|
---|
46 | };
|
---|
47 |
|
---|
48 | } // end namespace internal
|
---|
49 |
|
---|
50 | template<typename Derived> class ReturnByValue
|
---|
51 | : internal::no_assignment_operator, public internal::dense_xpr_base< ReturnByValue<Derived> >::type
|
---|
52 | {
|
---|
53 | public:
|
---|
54 | typedef typename internal::traits<Derived>::ReturnType ReturnType;
|
---|
55 |
|
---|
56 | typedef typename internal::dense_xpr_base<ReturnByValue>::type Base;
|
---|
57 | EIGEN_DENSE_PUBLIC_INTERFACE(ReturnByValue)
|
---|
58 |
|
---|
59 | template<typename Dest>
|
---|
60 | inline void evalTo(Dest& dst) const
|
---|
61 | { static_cast<const Derived*>(this)->evalTo(dst); }
|
---|
62 | inline Index rows() const { return static_cast<const Derived*>(this)->rows(); }
|
---|
63 | inline Index cols() const { return static_cast<const Derived*>(this)->cols(); }
|
---|
64 |
|
---|
65 | #ifndef EIGEN_PARSED_BY_DOXYGEN
|
---|
66 | #define Unusable YOU_ARE_TRYING_TO_ACCESS_A_SINGLE_COEFFICIENT_IN_A_SPECIAL_EXPRESSION_WHERE_THAT_IS_NOT_ALLOWED_BECAUSE_THAT_WOULD_BE_INEFFICIENT
|
---|
67 | class Unusable{
|
---|
68 | Unusable(const Unusable&) {}
|
---|
69 | Unusable& operator=(const Unusable&) {return *this;}
|
---|
70 | };
|
---|
71 | const Unusable& coeff(Index) const { return *reinterpret_cast<const Unusable*>(this); }
|
---|
72 | const Unusable& coeff(Index,Index) const { return *reinterpret_cast<const Unusable*>(this); }
|
---|
73 | Unusable& coeffRef(Index) { return *reinterpret_cast<Unusable*>(this); }
|
---|
74 | Unusable& coeffRef(Index,Index) { return *reinterpret_cast<Unusable*>(this); }
|
---|
75 | template<int LoadMode> Unusable& packet(Index) const;
|
---|
76 | template<int LoadMode> Unusable& packet(Index, Index) const;
|
---|
77 | #endif
|
---|
78 | };
|
---|
79 |
|
---|
80 | template<typename Derived>
|
---|
81 | template<typename OtherDerived>
|
---|
82 | Derived& DenseBase<Derived>::operator=(const ReturnByValue<OtherDerived>& other)
|
---|
83 | {
|
---|
84 | other.evalTo(derived());
|
---|
85 | return derived();
|
---|
86 | }
|
---|
87 |
|
---|
88 | template<typename Derived>
|
---|
89 | template<typename OtherDerived>
|
---|
90 | Derived& DenseBase<Derived>::lazyAssign(const ReturnByValue<OtherDerived>& other)
|
---|
91 | {
|
---|
92 | other.evalTo(derived());
|
---|
93 | return derived();
|
---|
94 | }
|
---|
95 |
|
---|
96 |
|
---|
97 | } // end namespace Eigen
|
---|
98 |
|
---|
99 | #endif // EIGEN_RETURNBYVALUE_H
|
---|