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1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2006-2010 Benoit Jacob <jacob.benoit.1@gmail.com>
5 //
6 // This Source Code Form is subject to the terms of the Mozilla
7 // Public License v. 2.0. If a copy of the MPL was not distributed
8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
9 
10 #ifndef EIGEN_DENSECOEFFSBASE_H
11 #define EIGEN_DENSECOEFFSBASE_H
12 
13 namespace Eigen {
14 
15 namespace internal {
16 template<typename T> struct add_const_on_value_type_if_arithmetic
17 {
18   typedef typename conditional<is_arithmetic<T>::value, T, typename add_const_on_value_type<T>::type>::type type;
19 };
20 }
21 
22 /** \brief Base class providing read-only coefficient access to matrices and arrays.
23   * \ingroup Core_Module
24   * \tparam Derived Type of the derived class
25   * \tparam #ReadOnlyAccessors Constant indicating read-only access
26   *
27   * This class defines the \c operator() \c const function and friends, which can be used to read specific
28   * entries of a matrix or array.
29   *
30   * \sa DenseCoeffsBase<Derived, WriteAccessors>, DenseCoeffsBase<Derived, DirectAccessors>,
31   *     \ref TopicClassHierarchy
32   */
33 template<typename Derived>
34 class DenseCoeffsBase<Derived,ReadOnlyAccessors> : public EigenBase<Derived>
35 {
36   public:
37     typedef typename internal::traits<Derived>::StorageKind StorageKind;
38     typedef typename internal::traits<Derived>::Scalar Scalar;
39     typedef typename internal::packet_traits<Scalar>::type PacketScalar;
40 
41     // Explanation for this CoeffReturnType typedef.
42     // - This is the return type of the coeff() method.
43     // - The LvalueBit means exactly that we can offer a coeffRef() method, which means exactly that we can get references
44     // to coeffs, which means exactly that we can have coeff() return a const reference (as opposed to returning a value).
45     // - The is_artihmetic check is required since "const int", "const double", etc. will cause warnings on some systems
46     // while the declaration of "const T", where T is a non arithmetic type does not. Always returning "const Scalar&" is
47     // not possible, since the underlying expressions might not offer a valid address the reference could be referring to.
48     typedef typename internal::conditional<bool(internal::traits<Derived>::Flags&LvalueBit),
49                          const Scalar&,
50                          typename internal::conditional<internal::is_arithmetic<Scalar>::value, Scalar, const Scalar>::type
51                      >::type CoeffReturnType;
52 
53     typedef typename internal::add_const_on_value_type_if_arithmetic<
54                          typename internal::packet_traits<Scalar>::type
55                      >::type PacketReturnType;
56 
57     typedef EigenBase<Derived> Base;
58     using Base::rows;
59     using Base::cols;
60     using Base::size;
61     using Base::derived;
62 
63     EIGEN_DEVICE_FUNC
rowIndexByOuterInner(Index outer,Index inner)64     EIGEN_STRONG_INLINE Index rowIndexByOuterInner(Index outer, Index inner) const
65     {
66       return int(Derived::RowsAtCompileTime) == 1 ? 0
67           : int(Derived::ColsAtCompileTime) == 1 ? inner
68           : int(Derived::Flags)&RowMajorBit ? outer
69           : inner;
70     }
71 
72     EIGEN_DEVICE_FUNC
colIndexByOuterInner(Index outer,Index inner)73     EIGEN_STRONG_INLINE Index colIndexByOuterInner(Index outer, Index inner) const
74     {
75       return int(Derived::ColsAtCompileTime) == 1 ? 0
76           : int(Derived::RowsAtCompileTime) == 1 ? inner
77           : int(Derived::Flags)&RowMajorBit ? inner
78           : outer;
79     }
80 
81     /** Short version: don't use this function, use
82       * \link operator()(Index,Index) const \endlink instead.
83       *
84       * Long version: this function is similar to
85       * \link operator()(Index,Index) const \endlink, but without the assertion.
86       * Use this for limiting the performance cost of debugging code when doing
87       * repeated coefficient access. Only use this when it is guaranteed that the
88       * parameters \a row and \a col are in range.
89       *
90       * If EIGEN_INTERNAL_DEBUGGING is defined, an assertion will be made, making this
91       * function equivalent to \link operator()(Index,Index) const \endlink.
92       *
93       * \sa operator()(Index,Index) const, coeffRef(Index,Index), coeff(Index) const
94       */
95     EIGEN_DEVICE_FUNC
coeff(Index row,Index col)96     EIGEN_STRONG_INLINE CoeffReturnType coeff(Index row, Index col) const
97     {
98       eigen_internal_assert(row >= 0 && row < rows()
99                          && col >= 0 && col < cols());
100       return internal::evaluator<Derived>(derived()).coeff(row,col);
101     }
102 
103     EIGEN_DEVICE_FUNC
coeffByOuterInner(Index outer,Index inner)104     EIGEN_STRONG_INLINE CoeffReturnType coeffByOuterInner(Index outer, Index inner) const
105     {
106       return coeff(rowIndexByOuterInner(outer, inner),
107                    colIndexByOuterInner(outer, inner));
108     }
109 
110     /** \returns the coefficient at given the given row and column.
111       *
112       * \sa operator()(Index,Index), operator[](Index)
113       */
114     EIGEN_DEVICE_FUNC
operator()115     EIGEN_STRONG_INLINE CoeffReturnType operator()(Index row, Index col) const
116     {
117       eigen_assert(row >= 0 && row < rows()
118           && col >= 0 && col < cols());
119       return coeff(row, col);
120     }
121 
122     /** Short version: don't use this function, use
123       * \link operator[](Index) const \endlink instead.
124       *
125       * Long version: this function is similar to
126       * \link operator[](Index) const \endlink, but without the assertion.
127       * Use this for limiting the performance cost of debugging code when doing
128       * repeated coefficient access. Only use this when it is guaranteed that the
129       * parameter \a index is in range.
130       *
131       * If EIGEN_INTERNAL_DEBUGGING is defined, an assertion will be made, making this
132       * function equivalent to \link operator[](Index) const \endlink.
133       *
134       * \sa operator[](Index) const, coeffRef(Index), coeff(Index,Index) const
135       */
136 
137     EIGEN_DEVICE_FUNC
138     EIGEN_STRONG_INLINE CoeffReturnType
coeff(Index index)139     coeff(Index index) const
140     {
141       EIGEN_STATIC_ASSERT(internal::evaluator<Derived>::Flags & LinearAccessBit,
142                           THIS_COEFFICIENT_ACCESSOR_TAKING_ONE_ACCESS_IS_ONLY_FOR_EXPRESSIONS_ALLOWING_LINEAR_ACCESS)
143       eigen_internal_assert(index >= 0 && index < size());
144       return internal::evaluator<Derived>(derived()).coeff(index);
145     }
146 
147 
148     /** \returns the coefficient at given index.
149       *
150       * This method is allowed only for vector expressions, and for matrix expressions having the LinearAccessBit.
151       *
152       * \sa operator[](Index), operator()(Index,Index) const, x() const, y() const,
153       * z() const, w() const
154       */
155 
156     EIGEN_DEVICE_FUNC
157     EIGEN_STRONG_INLINE CoeffReturnType
158     operator[](Index index) const
159     {
160       EIGEN_STATIC_ASSERT(Derived::IsVectorAtCompileTime,
161                           THE_BRACKET_OPERATOR_IS_ONLY_FOR_VECTORS__USE_THE_PARENTHESIS_OPERATOR_INSTEAD)
162       eigen_assert(index >= 0 && index < size());
163       return coeff(index);
164     }
165 
166     /** \returns the coefficient at given index.
167       *
168       * This is synonymous to operator[](Index) const.
169       *
170       * This method is allowed only for vector expressions, and for matrix expressions having the LinearAccessBit.
171       *
172       * \sa operator[](Index), operator()(Index,Index) const, x() const, y() const,
173       * z() const, w() const
174       */
175 
176     EIGEN_DEVICE_FUNC
177     EIGEN_STRONG_INLINE CoeffReturnType
operator()178     operator()(Index index) const
179     {
180       eigen_assert(index >= 0 && index < size());
181       return coeff(index);
182     }
183 
184     /** equivalent to operator[](0).  */
185 
186     EIGEN_DEVICE_FUNC
187     EIGEN_STRONG_INLINE CoeffReturnType
x()188     x() const { return (*this)[0]; }
189 
190     /** equivalent to operator[](1).  */
191 
192     EIGEN_DEVICE_FUNC
193     EIGEN_STRONG_INLINE CoeffReturnType
y()194     y() const
195     {
196       EIGEN_STATIC_ASSERT(Derived::SizeAtCompileTime==-1 || Derived::SizeAtCompileTime>=2, OUT_OF_RANGE_ACCESS);
197       return (*this)[1];
198     }
199 
200     /** equivalent to operator[](2).  */
201 
202     EIGEN_DEVICE_FUNC
203     EIGEN_STRONG_INLINE CoeffReturnType
z()204     z() const
205     {
206       EIGEN_STATIC_ASSERT(Derived::SizeAtCompileTime==-1 || Derived::SizeAtCompileTime>=3, OUT_OF_RANGE_ACCESS);
207       return (*this)[2];
208     }
209 
210     /** equivalent to operator[](3).  */
211 
212     EIGEN_DEVICE_FUNC
213     EIGEN_STRONG_INLINE CoeffReturnType
w()214     w() const
215     {
216       EIGEN_STATIC_ASSERT(Derived::SizeAtCompileTime==-1 || Derived::SizeAtCompileTime>=4, OUT_OF_RANGE_ACCESS);
217       return (*this)[3];
218     }
219 
220     /** \internal
221       * \returns the packet of coefficients starting at the given row and column. It is your responsibility
222       * to ensure that a packet really starts there. This method is only available on expressions having the
223       * PacketAccessBit.
224       *
225       * The \a LoadMode parameter may have the value \a #Aligned or \a #Unaligned. Its effect is to select
226       * the appropriate vectorization instruction. Aligned access is faster, but is only possible for packets
227       * starting at an address which is a multiple of the packet size.
228       */
229 
230     template<int LoadMode>
packet(Index row,Index col)231     EIGEN_STRONG_INLINE PacketReturnType packet(Index row, Index col) const
232     {
233       typedef typename internal::packet_traits<Scalar>::type DefaultPacketType;
234       eigen_internal_assert(row >= 0 && row < rows() && col >= 0 && col < cols());
235       return internal::evaluator<Derived>(derived()).template packet<LoadMode,DefaultPacketType>(row,col);
236     }
237 
238 
239     /** \internal */
240     template<int LoadMode>
packetByOuterInner(Index outer,Index inner)241     EIGEN_STRONG_INLINE PacketReturnType packetByOuterInner(Index outer, Index inner) const
242     {
243       return packet<LoadMode>(rowIndexByOuterInner(outer, inner),
244                               colIndexByOuterInner(outer, inner));
245     }
246 
247     /** \internal
248       * \returns the packet of coefficients starting at the given index. It is your responsibility
249       * to ensure that a packet really starts there. This method is only available on expressions having the
250       * PacketAccessBit and the LinearAccessBit.
251       *
252       * The \a LoadMode parameter may have the value \a #Aligned or \a #Unaligned. Its effect is to select
253       * the appropriate vectorization instruction. Aligned access is faster, but is only possible for packets
254       * starting at an address which is a multiple of the packet size.
255       */
256 
257     template<int LoadMode>
packet(Index index)258     EIGEN_STRONG_INLINE PacketReturnType packet(Index index) const
259     {
260       EIGEN_STATIC_ASSERT(internal::evaluator<Derived>::Flags & LinearAccessBit,
261                           THIS_COEFFICIENT_ACCESSOR_TAKING_ONE_ACCESS_IS_ONLY_FOR_EXPRESSIONS_ALLOWING_LINEAR_ACCESS)
262       typedef typename internal::packet_traits<Scalar>::type DefaultPacketType;
263       eigen_internal_assert(index >= 0 && index < size());
264       return internal::evaluator<Derived>(derived()).template packet<LoadMode,DefaultPacketType>(index);
265     }
266 
267   protected:
268     // explanation: DenseBase is doing "using ..." on the methods from DenseCoeffsBase.
269     // But some methods are only available in the DirectAccess case.
270     // So we add dummy methods here with these names, so that "using... " doesn't fail.
271     // It's not private so that the child class DenseBase can access them, and it's not public
272     // either since it's an implementation detail, so has to be protected.
273     void coeffRef();
274     void coeffRefByOuterInner();
275     void writePacket();
276     void writePacketByOuterInner();
277     void copyCoeff();
278     void copyCoeffByOuterInner();
279     void copyPacket();
280     void copyPacketByOuterInner();
281     void stride();
282     void innerStride();
283     void outerStride();
284     void rowStride();
285     void colStride();
286 };
287 
288 /** \brief Base class providing read/write coefficient access to matrices and arrays.
289   * \ingroup Core_Module
290   * \tparam Derived Type of the derived class
291   * \tparam #WriteAccessors Constant indicating read/write access
292   *
293   * This class defines the non-const \c operator() function and friends, which can be used to write specific
294   * entries of a matrix or array. This class inherits DenseCoeffsBase<Derived, ReadOnlyAccessors> which
295   * defines the const variant for reading specific entries.
296   *
297   * \sa DenseCoeffsBase<Derived, DirectAccessors>, \ref TopicClassHierarchy
298   */
299 template<typename Derived>
300 class DenseCoeffsBase<Derived, WriteAccessors> : public DenseCoeffsBase<Derived, ReadOnlyAccessors>
301 {
302   public:
303 
304     typedef DenseCoeffsBase<Derived, ReadOnlyAccessors> Base;
305 
306     typedef typename internal::traits<Derived>::StorageKind StorageKind;
307     typedef typename internal::traits<Derived>::Scalar Scalar;
308     typedef typename internal::packet_traits<Scalar>::type PacketScalar;
309     typedef typename NumTraits<Scalar>::Real RealScalar;
310 
311     using Base::coeff;
312     using Base::rows;
313     using Base::cols;
314     using Base::size;
315     using Base::derived;
316     using Base::rowIndexByOuterInner;
317     using Base::colIndexByOuterInner;
318     using Base::operator[];
319     using Base::operator();
320     using Base::x;
321     using Base::y;
322     using Base::z;
323     using Base::w;
324 
325     /** Short version: don't use this function, use
326       * \link operator()(Index,Index) \endlink instead.
327       *
328       * Long version: this function is similar to
329       * \link operator()(Index,Index) \endlink, but without the assertion.
330       * Use this for limiting the performance cost of debugging code when doing
331       * repeated coefficient access. Only use this when it is guaranteed that the
332       * parameters \a row and \a col are in range.
333       *
334       * If EIGEN_INTERNAL_DEBUGGING is defined, an assertion will be made, making this
335       * function equivalent to \link operator()(Index,Index) \endlink.
336       *
337       * \sa operator()(Index,Index), coeff(Index, Index) const, coeffRef(Index)
338       */
339     EIGEN_DEVICE_FUNC
coeffRef(Index row,Index col)340     EIGEN_STRONG_INLINE Scalar& coeffRef(Index row, Index col)
341     {
342       eigen_internal_assert(row >= 0 && row < rows()
343                          && col >= 0 && col < cols());
344       return internal::evaluator<Derived>(derived()).coeffRef(row,col);
345     }
346 
347     EIGEN_DEVICE_FUNC
348     EIGEN_STRONG_INLINE Scalar&
coeffRefByOuterInner(Index outer,Index inner)349     coeffRefByOuterInner(Index outer, Index inner)
350     {
351       return coeffRef(rowIndexByOuterInner(outer, inner),
352                       colIndexByOuterInner(outer, inner));
353     }
354 
355     /** \returns a reference to the coefficient at given the given row and column.
356       *
357       * \sa operator[](Index)
358       */
359 
360     EIGEN_DEVICE_FUNC
361     EIGEN_STRONG_INLINE Scalar&
operator()362     operator()(Index row, Index col)
363     {
364       eigen_assert(row >= 0 && row < rows()
365           && col >= 0 && col < cols());
366       return coeffRef(row, col);
367     }
368 
369 
370     /** Short version: don't use this function, use
371       * \link operator[](Index) \endlink instead.
372       *
373       * Long version: this function is similar to
374       * \link operator[](Index) \endlink, but without the assertion.
375       * Use this for limiting the performance cost of debugging code when doing
376       * repeated coefficient access. Only use this when it is guaranteed that the
377       * parameters \a row and \a col are in range.
378       *
379       * If EIGEN_INTERNAL_DEBUGGING is defined, an assertion will be made, making this
380       * function equivalent to \link operator[](Index) \endlink.
381       *
382       * \sa operator[](Index), coeff(Index) const, coeffRef(Index,Index)
383       */
384 
385     EIGEN_DEVICE_FUNC
386     EIGEN_STRONG_INLINE Scalar&
coeffRef(Index index)387     coeffRef(Index index)
388     {
389       EIGEN_STATIC_ASSERT(internal::evaluator<Derived>::Flags & LinearAccessBit,
390                           THIS_COEFFICIENT_ACCESSOR_TAKING_ONE_ACCESS_IS_ONLY_FOR_EXPRESSIONS_ALLOWING_LINEAR_ACCESS)
391       eigen_internal_assert(index >= 0 && index < size());
392       return internal::evaluator<Derived>(derived()).coeffRef(index);
393     }
394 
395     /** \returns a reference to the coefficient at given index.
396       *
397       * This method is allowed only for vector expressions, and for matrix expressions having the LinearAccessBit.
398       *
399       * \sa operator[](Index) const, operator()(Index,Index), x(), y(), z(), w()
400       */
401 
402     EIGEN_DEVICE_FUNC
403     EIGEN_STRONG_INLINE Scalar&
404     operator[](Index index)
405     {
406       EIGEN_STATIC_ASSERT(Derived::IsVectorAtCompileTime,
407                           THE_BRACKET_OPERATOR_IS_ONLY_FOR_VECTORS__USE_THE_PARENTHESIS_OPERATOR_INSTEAD)
408       eigen_assert(index >= 0 && index < size());
409       return coeffRef(index);
410     }
411 
412     /** \returns a reference to the coefficient at given index.
413       *
414       * This is synonymous to operator[](Index).
415       *
416       * This method is allowed only for vector expressions, and for matrix expressions having the LinearAccessBit.
417       *
418       * \sa operator[](Index) const, operator()(Index,Index), x(), y(), z(), w()
419       */
420 
421     EIGEN_DEVICE_FUNC
422     EIGEN_STRONG_INLINE Scalar&
operator()423     operator()(Index index)
424     {
425       eigen_assert(index >= 0 && index < size());
426       return coeffRef(index);
427     }
428 
429     /** equivalent to operator[](0).  */
430 
431     EIGEN_DEVICE_FUNC
432     EIGEN_STRONG_INLINE Scalar&
x()433     x() { return (*this)[0]; }
434 
435     /** equivalent to operator[](1).  */
436 
437     EIGEN_DEVICE_FUNC
438     EIGEN_STRONG_INLINE Scalar&
y()439     y()
440     {
441       EIGEN_STATIC_ASSERT(Derived::SizeAtCompileTime==-1 || Derived::SizeAtCompileTime>=2, OUT_OF_RANGE_ACCESS);
442       return (*this)[1];
443     }
444 
445     /** equivalent to operator[](2).  */
446 
447     EIGEN_DEVICE_FUNC
448     EIGEN_STRONG_INLINE Scalar&
z()449     z()
450     {
451       EIGEN_STATIC_ASSERT(Derived::SizeAtCompileTime==-1 || Derived::SizeAtCompileTime>=3, OUT_OF_RANGE_ACCESS);
452       return (*this)[2];
453     }
454 
455     /** equivalent to operator[](3).  */
456 
457     EIGEN_DEVICE_FUNC
458     EIGEN_STRONG_INLINE Scalar&
w()459     w()
460     {
461       EIGEN_STATIC_ASSERT(Derived::SizeAtCompileTime==-1 || Derived::SizeAtCompileTime>=4, OUT_OF_RANGE_ACCESS);
462       return (*this)[3];
463     }
464 };
465 
466 /** \brief Base class providing direct read-only coefficient access to matrices and arrays.
467   * \ingroup Core_Module
468   * \tparam Derived Type of the derived class
469   * \tparam #DirectAccessors Constant indicating direct access
470   *
471   * This class defines functions to work with strides which can be used to access entries directly. This class
472   * inherits DenseCoeffsBase<Derived, ReadOnlyAccessors> which defines functions to access entries read-only using
473   * \c operator() .
474   *
475   * \sa \blank \ref TopicClassHierarchy
476   */
477 template<typename Derived>
478 class DenseCoeffsBase<Derived, DirectAccessors> : public DenseCoeffsBase<Derived, ReadOnlyAccessors>
479 {
480   public:
481 
482     typedef DenseCoeffsBase<Derived, ReadOnlyAccessors> Base;
483     typedef typename internal::traits<Derived>::Scalar Scalar;
484     typedef typename NumTraits<Scalar>::Real RealScalar;
485 
486     using Base::rows;
487     using Base::cols;
488     using Base::size;
489     using Base::derived;
490 
491     /** \returns the pointer increment between two consecutive elements within a slice in the inner direction.
492       *
493       * \sa outerStride(), rowStride(), colStride()
494       */
495     EIGEN_DEVICE_FUNC
innerStride()496     inline Index innerStride() const
497     {
498       return derived().innerStride();
499     }
500 
501     /** \returns the pointer increment between two consecutive inner slices (for example, between two consecutive columns
502       *          in a column-major matrix).
503       *
504       * \sa innerStride(), rowStride(), colStride()
505       */
506     EIGEN_DEVICE_FUNC
outerStride()507     inline Index outerStride() const
508     {
509       return derived().outerStride();
510     }
511 
512     // FIXME shall we remove it ?
stride()513     inline Index stride() const
514     {
515       return Derived::IsVectorAtCompileTime ? innerStride() : outerStride();
516     }
517 
518     /** \returns the pointer increment between two consecutive rows.
519       *
520       * \sa innerStride(), outerStride(), colStride()
521       */
522     EIGEN_DEVICE_FUNC
rowStride()523     inline Index rowStride() const
524     {
525       return Derived::IsRowMajor ? outerStride() : innerStride();
526     }
527 
528     /** \returns the pointer increment between two consecutive columns.
529       *
530       * \sa innerStride(), outerStride(), rowStride()
531       */
532     EIGEN_DEVICE_FUNC
colStride()533     inline Index colStride() const
534     {
535       return Derived::IsRowMajor ? innerStride() : outerStride();
536     }
537 };
538 
539 /** \brief Base class providing direct read/write coefficient access to matrices and arrays.
540   * \ingroup Core_Module
541   * \tparam Derived Type of the derived class
542   * \tparam #DirectWriteAccessors Constant indicating direct access
543   *
544   * This class defines functions to work with strides which can be used to access entries directly. This class
545   * inherits DenseCoeffsBase<Derived, WriteAccessors> which defines functions to access entries read/write using
546   * \c operator().
547   *
548   * \sa \blank \ref TopicClassHierarchy
549   */
550 template<typename Derived>
551 class DenseCoeffsBase<Derived, DirectWriteAccessors>
552   : public DenseCoeffsBase<Derived, WriteAccessors>
553 {
554   public:
555 
556     typedef DenseCoeffsBase<Derived, WriteAccessors> Base;
557     typedef typename internal::traits<Derived>::Scalar Scalar;
558     typedef typename NumTraits<Scalar>::Real RealScalar;
559 
560     using Base::rows;
561     using Base::cols;
562     using Base::size;
563     using Base::derived;
564 
565     /** \returns the pointer increment between two consecutive elements within a slice in the inner direction.
566       *
567       * \sa outerStride(), rowStride(), colStride()
568       */
569     EIGEN_DEVICE_FUNC
innerStride()570     inline Index innerStride() const
571     {
572       return derived().innerStride();
573     }
574 
575     /** \returns the pointer increment between two consecutive inner slices (for example, between two consecutive columns
576       *          in a column-major matrix).
577       *
578       * \sa innerStride(), rowStride(), colStride()
579       */
580     EIGEN_DEVICE_FUNC
outerStride()581     inline Index outerStride() const
582     {
583       return derived().outerStride();
584     }
585 
586     // FIXME shall we remove it ?
stride()587     inline Index stride() const
588     {
589       return Derived::IsVectorAtCompileTime ? innerStride() : outerStride();
590     }
591 
592     /** \returns the pointer increment between two consecutive rows.
593       *
594       * \sa innerStride(), outerStride(), colStride()
595       */
596     EIGEN_DEVICE_FUNC
rowStride()597     inline Index rowStride() const
598     {
599       return Derived::IsRowMajor ? outerStride() : innerStride();
600     }
601 
602     /** \returns the pointer increment between two consecutive columns.
603       *
604       * \sa innerStride(), outerStride(), rowStride()
605       */
606     EIGEN_DEVICE_FUNC
colStride()607     inline Index colStride() const
608     {
609       return Derived::IsRowMajor ? innerStride() : outerStride();
610     }
611 };
612 
613 namespace internal {
614 
615 template<int Alignment, typename Derived, bool JustReturnZero>
616 struct first_aligned_impl
617 {
runfirst_aligned_impl618   static inline Index run(const Derived&)
619   { return 0; }
620 };
621 
622 template<int Alignment, typename Derived>
623 struct first_aligned_impl<Alignment, Derived, false>
624 {
625   static inline Index run(const Derived& m)
626   {
627     return internal::first_aligned<Alignment>(m.data(), m.size());
628   }
629 };
630 
631 /** \internal \returns the index of the first element of the array stored by \a m that is properly aligned with respect to \a Alignment for vectorization.
632   *
633   * \tparam Alignment requested alignment in Bytes.
634   *
635   * There is also the variant first_aligned(const Scalar*, Integer) defined in Memory.h. See it for more
636   * documentation.
637   */
638 template<int Alignment, typename Derived>
639 static inline Index first_aligned(const DenseBase<Derived>& m)
640 {
641   enum { ReturnZero = (int(evaluator<Derived>::Alignment) >= Alignment) || !(Derived::Flags & DirectAccessBit) };
642   return first_aligned_impl<Alignment, Derived, ReturnZero>::run(m.derived());
643 }
644 
645 template<typename Derived>
646 static inline Index first_default_aligned(const DenseBase<Derived>& m)
647 {
648   typedef typename Derived::Scalar Scalar;
649   typedef typename packet_traits<Scalar>::type DefaultPacketType;
650   return internal::first_aligned<int(unpacket_traits<DefaultPacketType>::alignment),Derived>(m);
651 }
652 
653 template<typename Derived, bool HasDirectAccess = has_direct_access<Derived>::ret>
654 struct inner_stride_at_compile_time
655 {
656   enum { ret = traits<Derived>::InnerStrideAtCompileTime };
657 };
658 
659 template<typename Derived>
660 struct inner_stride_at_compile_time<Derived, false>
661 {
662   enum { ret = 0 };
663 };
664 
665 template<typename Derived, bool HasDirectAccess = has_direct_access<Derived>::ret>
666 struct outer_stride_at_compile_time
667 {
668   enum { ret = traits<Derived>::OuterStrideAtCompileTime };
669 };
670 
671 template<typename Derived>
672 struct outer_stride_at_compile_time<Derived, false>
673 {
674   enum { ret = 0 };
675 };
676 
677 } // end namespace internal
678 
679 } // end namespace Eigen
680 
681 #endif // EIGEN_DENSECOEFFSBASE_H
682