1 // Copyright 2002 The Trustees of Indiana University.

     2 

     3 // Use, modification and distribution is subject to the Boost Software 

     4 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at

     5 // http://www.boost.org/LICENSE_1_0.txt)

     6 

     7 //  Boost.MultiArray Library

     8 //  Authors: Ronald Garcia

     9 //           Jeremy Siek

    10 //           Andrew Lumsdaine

    11 //  See http://www.boost.org/libs/multi_array for documentation.

    12 

    13 #ifndef BOOST_MULTI_ARRAY_VIEW_RG071301_HPP

    14 #define BOOST_MULTI_ARRAY_VIEW_RG071301_HPP

    15 

    16 //

    17 // view.hpp - code for creating "views" of array data.

    18 //

    19 

    20 #include "boost/multi_array/base.hpp"

    21 #include "boost/multi_array/concept_checks.hpp"

    22 #include "boost/multi_array/iterator.hpp"

    23 #include "boost/multi_array/storage_order.hpp"

    24 #include "boost/multi_array/subarray.hpp"

    25 #include "boost/multi_array/algorithm.hpp"

    26 #include "boost/type_traits/is_integral.hpp"

    27 #include "boost/array.hpp"

    28 #include "boost/limits.hpp"

    29 #include <algorithm>

    30 #include <cstddef>

    31 #include <functional>

    32 #include <numeric>

    33 

    34 namespace boost {

    35 namespace detail {

    36 namespace multi_array {

    37 

    38 // TPtr = const T* defaulted in base.hpp

    39 template <typename T, std::size_t NumDims, typename TPtr>

    40 class const_multi_array_view :

    41     public boost::detail::multi_array::multi_array_impl_base<T,NumDims>

    42 {

    43   typedef boost::detail::multi_array::multi_array_impl_base<T,NumDims> super_type;

    44 public: 

    45   typedef typename super_type::value_type value_type;

    46   typedef typename super_type::const_reference const_reference;

    47   typedef typename super_type::const_iterator const_iterator;

    48   typedef typename super_type::const_reverse_iterator const_reverse_iterator;

    49   typedef typename super_type::element element;

    50   typedef typename super_type::size_type size_type;

    51   typedef typename super_type::difference_type difference_type;

    52   typedef typename super_type::index index;

    53   typedef typename super_type::extent_range extent_range;

    54 

    55   // template typedefs

    56   template <std::size_t NDims>

    57   struct const_array_view {

    58     typedef boost::detail::multi_array::const_multi_array_view<T,NDims> type;

    59   };

    60 

    61   template <std::size_t NDims>

    62   struct array_view {

    63     typedef boost::detail::multi_array::multi_array_view<T,NDims> type;

    64   };

    65 

    66   template <typename OPtr>

    67   const_multi_array_view(const 

    68                          const_multi_array_view<T,NumDims,OPtr>& other) :

    69     base_(other.base_), origin_offset_(other.origin_offset_),

    70     num_elements_(other.num_elements_), extent_list_(other.extent_list_),

    71     stride_list_(other.stride_list_), index_base_list_(other.index_base_list_)

    72   { }

    73 

    74 

    75   template <class BaseList>

    76 #ifdef BOOST_NO_SFINAE

    77   void

    78 #else

    79   typename

    80   disable_if<typename boost::is_integral<BaseList>::type,void >::type

    81 #endif

    82   reindex(const BaseList& values) {

    83     boost::function_requires<

    84       detail::multi_array::CollectionConcept<BaseList> >();

    85     boost::detail::multi_array::

    86       copy_n(values.begin(),num_dimensions(),index_base_list_.begin());

    87     origin_offset_ =

    88       this->calculate_indexing_offset(stride_list_,index_base_list_);

    89   }

    90 

    91   void reindex(index value) {

    92     index_base_list_.assign(value);

    93     origin_offset_ =

    94       this->calculate_indexing_offset(stride_list_,index_base_list_);

    95   }

    96 

    97   size_type num_dimensions() const { return NumDims; }

    98 

    99   size_type size() const { return extent_list_.front(); }

   100   size_type max_size() const { return num_elements(); }

   101   bool empty() const { return size() == 0; }

   102 

   103   const size_type* shape() const {

   104     return extent_list_.data();

   105   }

   106 

   107   const index* strides() const {

   108     return stride_list_.data();

   109   }

   110 

   111   const T* origin() const { return base_+origin_offset_; }

   112 

   113   size_type num_elements() const { return num_elements_; }

   114 

   115   const index* index_bases() const {

   116     return index_base_list_.data();

   117   }

   118 

   119   template <typename IndexList>

   120   const element& operator()(IndexList indices) const {

   121     boost::function_requires<

   122       detail::multi_array::CollectionConcept<IndexList> >();

   123     return super_type::access_element(boost::type<const element&>(),

   124                                       indices,origin(),

   125                                       shape(),strides(),index_bases());

   126   }

   127 

   128   // Only allow const element access

   129   const_reference operator[](index idx) const {

   130     return super_type::access(boost::type<const_reference>(),

   131                               idx,origin(),

   132                               shape(),strides(),

   133                               index_bases());

   134   }

   135 

   136   // see generate_array_view in base.hpp

   137 #if !defined(BOOST_MSVC) || BOOST_MSVC > 1300

   138   template <int NDims>

   139 #else

   140   template <int NumDims, int NDims> // else ICE

   141 #endif // BOOST_MSVC

   142   typename const_array_view<NDims>::type 

   143   operator[](const boost::detail::multi_array::

   144              index_gen<NumDims,NDims>& indices)

   145     const {

   146     typedef typename const_array_view<NDims>::type return_type;

   147     return

   148       super_type::generate_array_view(boost::type<return_type>(),

   149                                       indices,

   150                                       shape(),

   151                                       strides(),

   152                                       index_bases(),

   153                                       origin());

   154   }

   155   const_iterator begin() const {

   156     return const_iterator(*index_bases(),origin(),

   157                           shape(),strides(),index_bases());

   158   }

   159 

   160   const_iterator end() const {

   161     return const_iterator(*index_bases()+(index)*shape(),origin(),

   162                           shape(),strides(),index_bases());

   163   }

   164   

   165   const_reverse_iterator rbegin() const {

   166     return const_reverse_iterator(end());

   167   }

   168 

   169   const_reverse_iterator rend() const {

   170     return const_reverse_iterator(begin());

   171   }

   172 

   173 

   174   template <typename OPtr>

   175   bool operator==(const

   176                   const_multi_array_view<T,NumDims,OPtr>& rhs)

   177     const {

   178     if(std::equal(extent_list_.begin(),

   179                   extent_list_.end(),

   180                   rhs.extent_list_.begin()))

   181       return std::equal(begin(),end(),rhs.begin());

   182     else return false;

   183   }

   184 

   185   template <typename OPtr>

   186   bool operator<(const

   187                  const_multi_array_view<T,NumDims,OPtr>& rhs)

   188     const {

   189     return std::lexicographical_compare(begin(),end(),rhs.begin(),rhs.end());

   190   }

   191 

   192   template <typename OPtr>

   193   bool operator!=(const

   194                   const_multi_array_view<T,NumDims,OPtr>& rhs)

   195     const {

   196     return !(*this == rhs);

   197   }

   198 

   199   template <typename OPtr>

   200   bool operator>(const

   201                  const_multi_array_view<T,NumDims,OPtr>& rhs)

   202     const {

   203     return rhs < *this;

   204   }

   205 

   206   template <typename OPtr>

   207   bool operator<=(const

   208                  const_multi_array_view<T,NumDims,OPtr>& rhs)

   209     const {

   210     return !(*this > rhs);

   211   }

   212 

   213   template <typename OPtr>

   214   bool operator>=(const

   215                  const_multi_array_view<T,NumDims,OPtr>& rhs)

   216     const {

   217     return !(*this < rhs);

   218   }

   219 

   220 

   221 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS

   222 protected:

   223   template <typename,std::size_t> friend class multi_array_impl_base;

   224   template <typename,std::size_t,typename> friend class const_multi_array_view;

   225 #else

   226 public: // should be protected

   227 #endif

   228 

   229   // This constructor is used by multi_array_impl_base::generate_array_view

   230   // to create strides  

   231   template <typename ExtentList, typename Index>

   232   explicit const_multi_array_view(TPtr base,

   233                            const ExtentList& extents,

   234                            const boost::array<Index,NumDims>& strides): 

   235     base_(base), origin_offset_(0) {

   236 

   237     index_base_list_.assign(0);

   238 

   239     // Get the extents and strides

   240     boost::detail::multi_array::

   241       copy_n(extents.begin(),NumDims,extent_list_.begin());

   242     boost::detail::multi_array::

   243       copy_n(strides.begin(),NumDims,stride_list_.begin());

   244 

   245     // Calculate the array size

   246     num_elements_ = std::accumulate(extent_list_.begin(),extent_list_.end(),

   247                             size_type(1),std::multiplies<size_type>());

   248 #if 0

   249     assert(num_elements_ != 0);

   250 #endif

   251   }

   252 

   253   typedef boost::array<size_type,NumDims> size_list;

   254   typedef boost::array<index,NumDims> index_list;

   255 

   256   TPtr base_;

   257   index origin_offset_;

   258   size_type num_elements_;

   259   size_list extent_list_;

   260   index_list stride_list_;

   261   index_list index_base_list_;

   262 

   263 private:

   264   // const_multi_array_view cannot be assigned to (no deep copies!)

   265   const_multi_array_view& operator=(const const_multi_array_view& other);

   266 };

   267 

   268 

   269 template <typename T, std::size_t NumDims>

   270 class multi_array_view :

   271   public const_multi_array_view<T,NumDims,T*>

   272 {

   273   typedef const_multi_array_view<T,NumDims,T*> super_type;

   274 public: 

   275   typedef typename super_type::value_type value_type;

   276   typedef typename super_type::reference reference;

   277   typedef typename super_type::iterator iterator;

   278   typedef typename super_type::reverse_iterator reverse_iterator;

   279   typedef typename super_type::const_reference const_reference;

   280   typedef typename super_type::const_iterator const_iterator;

   281   typedef typename super_type::const_reverse_iterator const_reverse_iterator;

   282   typedef typename super_type::element element;

   283   typedef typename super_type::size_type size_type;

   284   typedef typename super_type::difference_type difference_type;

   285   typedef typename super_type::index index;

   286   typedef typename super_type::extent_range extent_range;

   287 

   288   // template typedefs

   289   template <std::size_t NDims>

   290   struct const_array_view {

   291     typedef boost::detail::multi_array::const_multi_array_view<T,NDims> type;

   292   };

   293 

   294   template <std::size_t NDims>

   295   struct array_view {

   296     typedef boost::detail::multi_array::multi_array_view<T,NDims> type;

   297   };

   298 

   299   // Assignment from other ConstMultiArray types.

   300   template <typename ConstMultiArray>

   301   multi_array_view& operator=(const ConstMultiArray& other) {

   302     function_requires< 

   303       boost::detail::multi_array::

   304       ConstMultiArrayConcept<ConstMultiArray,NumDims> >();

   305 

   306     // make sure the dimensions agree

   307     assert(other.num_dimensions() == this->num_dimensions());

   308     assert(std::equal(other.shape(),other.shape()+this->num_dimensions(),

   309                       this->shape()));

   310     // iterator-based copy

   311     std::copy(other.begin(),other.end(),begin());

   312     return *this;

   313   }

   314 

   315 

   316   multi_array_view& operator=(const multi_array_view& other) {

   317     if (&other != this) {

   318       // make sure the dimensions agree

   319       assert(other.num_dimensions() == this->num_dimensions());

   320       assert(std::equal(other.shape(),other.shape()+this->num_dimensions(),

   321                         this->shape()));

   322       // iterator-based copy

   323       std::copy(other.begin(),other.end(),begin());

   324     }

   325     return *this;

   326   }

   327 

   328   element* origin() { return this->base_+this->origin_offset_; }

   329 

   330   template <class IndexList>

   331   element& operator()(const IndexList& indices) {

   332     boost::function_requires<

   333       detail::multi_array::CollectionConcept<IndexList> >();

   334     return super_type::access_element(boost::type<element&>(),

   335                                       indices,origin(),

   336                                       this->shape(),this->strides(),

   337                                       this->index_bases());

   338   }

   339 

   340 

   341   reference operator[](index idx) {

   342     return super_type::access(boost::type<reference>(),

   343                               idx,origin(),

   344                               this->shape(),this->strides(),

   345                               this->index_bases());

   346   }

   347 

   348 

   349   // see generate_array_view in base.hpp

   350 #if !defined(BOOST_MSVC) || BOOST_MSVC > 1300

   351   template <int NDims>

   352 #else

   353   template <int NumDims, int NDims> // else ICE

   354 #endif // BOOST_MSVC

   355   typename array_view<NDims>::type 

   356   operator[](const boost::detail::multi_array::

   357              index_gen<NumDims,NDims>& indices) {

   358     typedef typename array_view<NDims>::type return_type;

   359     return

   360       super_type::generate_array_view(boost::type<return_type>(),

   361                                       indices,

   362                                       this->shape(),

   363                                       this->strides(),

   364                                       this->index_bases(),

   365                                       origin());

   366   }

   367   

   368   

   369   iterator begin() {

   370     return iterator(*this->index_bases(),origin(),

   371                     this->shape(),this->strides(),

   372                     this->index_bases());

   373   }

   374 

   375   iterator end() {

   376     return iterator(*this->index_bases()+(index)*this->shape(),origin(),

   377                     this->shape(),this->strides(),

   378                     this->index_bases());

   379   }

   380 

   381   reverse_iterator rbegin() {

   382     return reverse_iterator(end());

   383   }

   384 

   385   reverse_iterator rend() {

   386     return reverse_iterator(begin());

   387   }

   388 

   389   // Using declarations don't seem to work for g++

   390   // These are the proxies to work around this.

   391 

   392   const element* origin() const { return super_type::origin(); }

   393 

   394   template <class IndexList>

   395   const element& operator()(const IndexList& indices) const {

   396     boost::function_requires<

   397       detail::multi_array::CollectionConcept<IndexList> >();

   398     return super_type::operator()(indices);

   399   }

   400 

   401   const_reference operator[](index idx) const {

   402     return super_type::operator[](idx);

   403   }

   404 

   405   // see generate_array_view in base.hpp

   406 #if !defined(BOOST_MSVC) || BOOST_MSVC > 1300

   407   template <int NDims>

   408 #else

   409   template <int NumDims, int NDims> // else ICE

   410 #endif // BOOST_MSVC

   411   typename const_array_view<NDims>::type 

   412   operator[](const boost::detail::multi_array::

   413              index_gen<NumDims,NDims>& indices)

   414     const {

   415     return super_type::operator[](indices);

   416   }

   417   

   418   const_iterator begin() const {

   419     return super_type::begin();

   420   }

   421 

   422   const_iterator end() const {

   423     return super_type::end();

   424   }

   425 

   426   const_reverse_iterator rbegin() const {

   427     return super_type::rbegin();

   428   }

   429 

   430   const_reverse_iterator rend() const {

   431     return super_type::rend();

   432   }

   433 

   434 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS

   435 private:

   436   template <typename,std::size_t> friend class multi_array_impl_base;

   437 #else

   438 public: // should be private

   439 #endif

   440 

   441   // constructor used by multi_array_impl_base::generate_array_view to

   442   // generate array views

   443   template <typename ExtentList, typename Index>

   444   explicit multi_array_view(T* base,

   445                             const ExtentList& extents,

   446                             const boost::array<Index,NumDims>& strides) :

   447     super_type(base,extents,strides) { }

   448 

   449 };

   450 

   451 } // namespace multi_array

   452 } // namespace detail

   453 

   454 //

   455 // traits classes to get array_view types

   456 //

   457 template <typename Array, int N>

   458 class array_view_gen {

   459   typedef typename Array::element element;

   460 public:

   461   typedef boost::detail::multi_array::multi_array_view<element,N> type;

   462 };

   463 

   464 template <typename Array, int N>

   465 class const_array_view_gen {

   466   typedef typename Array::element element;

   467 public:

   468   typedef boost::detail::multi_array::const_multi_array_view<element,N> type;  

   469 };

   470 

   471 } // namespace boost

   472 

   473 #endif // BOOST_MULTI_ARRAY_VIEW_RG071301_HPP

   474