1 // Copyright 2002 The Trustees of Indiana University.
 
     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)
 
     7 //  Boost.MultiArray Library
 
     8 //  Authors: Ronald Garcia
 
    11 //  See http://www.boost.org/libs/multi_array for documentation.
 
    13 #ifndef BOOST_MULTI_ARRAY_VIEW_RG071301_HPP
 
    14 #define BOOST_MULTI_ARRAY_VIEW_RG071301_HPP
 
    17 // view.hpp - code for creating "views" of array data.
 
    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"
 
    36 namespace multi_array {
 
    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>
 
    43   typedef boost::detail::multi_array::multi_array_impl_base<T,NumDims> super_type;
 
    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;
 
    56   template <std::size_t NDims>
 
    57   struct const_array_view {
 
    58     typedef boost::detail::multi_array::const_multi_array_view<T,NDims> type;
 
    61   template <std::size_t NDims>
 
    63     typedef boost::detail::multi_array::multi_array_view<T,NDims> type;
 
    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_)
 
    75   template <class BaseList>
 
    76 #ifdef BOOST_NO_SFINAE
 
    80   disable_if<typename boost::is_integral<BaseList>::type,void >::type
 
    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());
 
    88       this->calculate_indexing_offset(stride_list_,index_base_list_);
 
    91   void reindex(index value) {
 
    92     index_base_list_.assign(value);
 
    94       this->calculate_indexing_offset(stride_list_,index_base_list_);
 
    97   size_type num_dimensions() const { return NumDims; }
 
    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; }
 
   103   const size_type* shape() const {
 
   104     return extent_list_.data();
 
   107   const index* strides() const {
 
   108     return stride_list_.data();
 
   111   const T* origin() const { return base_+origin_offset_; }
 
   113   size_type num_elements() const { return num_elements_; }
 
   115   const index* index_bases() const {
 
   116     return index_base_list_.data();
 
   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&>(),
 
   125                                       shape(),strides(),index_bases());
 
   128   // Only allow const element access
 
   129   const_reference operator[](index idx) const {
 
   130     return super_type::access(boost::type<const_reference>(),
 
   136   // see generate_array_view in base.hpp
 
   137 #if !defined(BOOST_MSVC) || BOOST_MSVC > 1300
 
   140   template <int NumDims, int NDims> // else ICE
 
   142   typename const_array_view<NDims>::type 
 
   143   operator[](const boost::detail::multi_array::
 
   144              index_gen<NumDims,NDims>& indices)
 
   146     typedef typename const_array_view<NDims>::type return_type;
 
   148       super_type::generate_array_view(boost::type<return_type>(),
 
   155   const_iterator begin() const {
 
   156     return const_iterator(*index_bases(),origin(),
 
   157                           shape(),strides(),index_bases());
 
   160   const_iterator end() const {
 
   161     return const_iterator(*index_bases()+(index)*shape(),origin(),
 
   162                           shape(),strides(),index_bases());
 
   165   const_reverse_iterator rbegin() const {
 
   166     return const_reverse_iterator(end());
 
   169   const_reverse_iterator rend() const {
 
   170     return const_reverse_iterator(begin());
 
   174   template <typename OPtr>
 
   175   bool operator==(const
 
   176                   const_multi_array_view<T,NumDims,OPtr>& rhs)
 
   178     if(std::equal(extent_list_.begin(),
 
   180                   rhs.extent_list_.begin()))
 
   181       return std::equal(begin(),end(),rhs.begin());
 
   185   template <typename OPtr>
 
   187                  const_multi_array_view<T,NumDims,OPtr>& rhs)
 
   189     return std::lexicographical_compare(begin(),end(),rhs.begin(),rhs.end());
 
   192   template <typename OPtr>
 
   193   bool operator!=(const
 
   194                   const_multi_array_view<T,NumDims,OPtr>& rhs)
 
   196     return !(*this == rhs);
 
   199   template <typename OPtr>
 
   201                  const_multi_array_view<T,NumDims,OPtr>& rhs)
 
   206   template <typename OPtr>
 
   207   bool operator<=(const
 
   208                  const_multi_array_view<T,NumDims,OPtr>& rhs)
 
   210     return !(*this > rhs);
 
   213   template <typename OPtr>
 
   214   bool operator>=(const
 
   215                  const_multi_array_view<T,NumDims,OPtr>& rhs)
 
   217     return !(*this < rhs);
 
   221 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
 
   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;
 
   226 public: // should be protected
 
   229   // This constructor is used by multi_array_impl_base::generate_array_view
 
   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) {
 
   237     index_base_list_.assign(0);
 
   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());
 
   245     // Calculate the array size
 
   246     num_elements_ = std::accumulate(extent_list_.begin(),extent_list_.end(),
 
   247                             size_type(1),std::multiplies<size_type>());
 
   249     assert(num_elements_ != 0);
 
   253   typedef boost::array<size_type,NumDims> size_list;
 
   254   typedef boost::array<index,NumDims> index_list;
 
   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_;
 
   264   // const_multi_array_view cannot be assigned to (no deep copies!)
 
   265   const_multi_array_view& operator=(const const_multi_array_view& other);
 
   269 template <typename T, std::size_t NumDims>
 
   270 class multi_array_view :
 
   271   public const_multi_array_view<T,NumDims,T*>
 
   273   typedef const_multi_array_view<T,NumDims,T*> super_type;
 
   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;
 
   289   template <std::size_t NDims>
 
   290   struct const_array_view {
 
   291     typedef boost::detail::multi_array::const_multi_array_view<T,NDims> type;
 
   294   template <std::size_t NDims>
 
   296     typedef boost::detail::multi_array::multi_array_view<T,NDims> type;
 
   299   // Assignment from other ConstMultiArray types.
 
   300   template <typename ConstMultiArray>
 
   301   multi_array_view& operator=(const ConstMultiArray& other) {
 
   303       boost::detail::multi_array::
 
   304       ConstMultiArrayConcept<ConstMultiArray,NumDims> >();
 
   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(),
 
   310     // iterator-based copy
 
   311     std::copy(other.begin(),other.end(),begin());
 
   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(),
 
   322       // iterator-based copy
 
   323       std::copy(other.begin(),other.end(),begin());
 
   328   element* origin() { return this->base_+this->origin_offset_; }
 
   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&>(),
 
   336                                       this->shape(),this->strides(),
 
   337                                       this->index_bases());
 
   341   reference operator[](index idx) {
 
   342     return super_type::access(boost::type<reference>(),
 
   344                               this->shape(),this->strides(),
 
   345                               this->index_bases());
 
   349   // see generate_array_view in base.hpp
 
   350 #if !defined(BOOST_MSVC) || BOOST_MSVC > 1300
 
   353   template <int NumDims, int NDims> // else ICE
 
   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;
 
   360       super_type::generate_array_view(boost::type<return_type>(),
 
   370     return iterator(*this->index_bases(),origin(),
 
   371                     this->shape(),this->strides(),
 
   372                     this->index_bases());
 
   376     return iterator(*this->index_bases()+(index)*this->shape(),origin(),
 
   377                     this->shape(),this->strides(),
 
   378                     this->index_bases());
 
   381   reverse_iterator rbegin() {
 
   382     return reverse_iterator(end());
 
   385   reverse_iterator rend() {
 
   386     return reverse_iterator(begin());
 
   389   // Using declarations don't seem to work for g++
 
   390   // These are the proxies to work around this.
 
   392   const element* origin() const { return super_type::origin(); }
 
   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);
 
   401   const_reference operator[](index idx) const {
 
   402     return super_type::operator[](idx);
 
   405   // see generate_array_view in base.hpp
 
   406 #if !defined(BOOST_MSVC) || BOOST_MSVC > 1300
 
   409   template <int NumDims, int NDims> // else ICE
 
   411   typename const_array_view<NDims>::type 
 
   412   operator[](const boost::detail::multi_array::
 
   413              index_gen<NumDims,NDims>& indices)
 
   415     return super_type::operator[](indices);
 
   418   const_iterator begin() const {
 
   419     return super_type::begin();
 
   422   const_iterator end() const {
 
   423     return super_type::end();
 
   426   const_reverse_iterator rbegin() const {
 
   427     return super_type::rbegin();
 
   430   const_reverse_iterator rend() const {
 
   431     return super_type::rend();
 
   434 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
 
   436   template <typename,std::size_t> friend class multi_array_impl_base;
 
   438 public: // should be private
 
   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) { }
 
   451 } // namespace multi_array
 
   452 } // namespace detail
 
   455 // traits classes to get array_view types
 
   457 template <typename Array, int N>
 
   458 class array_view_gen {
 
   459   typedef typename Array::element element;
 
   461   typedef boost::detail::multi_array::multi_array_view<element,N> type;
 
   464 template <typename Array, int N>
 
   465 class const_array_view_gen {
 
   466   typedef typename Array::element element;
 
   468   typedef boost::detail::multi_array::const_multi_array_view<element,N> type;  
 
   473 #endif // BOOST_MULTI_ARRAY_VIEW_RG071301_HPP