sl@0: // Copyright 2002 The Trustees of Indiana University.
sl@0: 
sl@0: // Use, modification and distribution is subject to the Boost Software 
sl@0: // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
sl@0: // http://www.boost.org/LICENSE_1_0.txt)
sl@0: 
sl@0: //  Boost.MultiArray Library
sl@0: //  Authors: Ronald Garcia
sl@0: //           Jeremy Siek
sl@0: //           Andrew Lumsdaine
sl@0: //  See http://www.boost.org/libs/multi_array for documentation.
sl@0: 
sl@0: #ifndef BASE_RG071801_HPP
sl@0: #define BASE_RG071801_HPP
sl@0: 
sl@0: //
sl@0: // base.hpp - some implementation base classes for from which
sl@0: // functionality is acquired
sl@0: //
sl@0: 
sl@0: #include "boost/multi_array/extent_range.hpp"
sl@0: #include "boost/multi_array/extent_gen.hpp"
sl@0: #include "boost/multi_array/index_range.hpp"
sl@0: #include "boost/multi_array/index_gen.hpp"
sl@0: #include "boost/multi_array/storage_order.hpp"
sl@0: #include "boost/multi_array/types.hpp"
sl@0: #include "boost/config.hpp"
sl@0: #include "boost/multi_array/concept_checks.hpp" //for ignore_unused_...
sl@0: #include "boost/mpl/eval_if.hpp"
sl@0: #include "boost/mpl/if.hpp"
sl@0: #include "boost/mpl/size_t.hpp"
sl@0: #include "boost/mpl/aux_/msvc_eti_base.hpp"
sl@0: #include "boost/iterator/reverse_iterator.hpp"
sl@0: #include "boost/static_assert.hpp"
sl@0: #include "boost/type.hpp"
sl@0: #include "boost/assert.hpp"
sl@0: #include <cstddef>
sl@0: #include <memory>
sl@0: 
sl@0: namespace boost {
sl@0: 
sl@0: /////////////////////////////////////////////////////////////////////////
sl@0: // class declarations
sl@0: /////////////////////////////////////////////////////////////////////////
sl@0: 
sl@0: template<typename T, std::size_t NumDims,
sl@0:   typename Allocator = std::allocator<T> >
sl@0: class multi_array;
sl@0: 
sl@0: // This is a public interface for use by end users!
sl@0: namespace multi_array_types {
sl@0:   typedef boost::detail::multi_array::size_type size_type;
sl@0:   typedef std::ptrdiff_t difference_type;
sl@0:   typedef boost::detail::multi_array::index index;
sl@0:   typedef detail::multi_array::index_range<index,size_type> index_range;
sl@0:   typedef detail::multi_array::extent_range<index,size_type> extent_range;
sl@0:   typedef detail::multi_array::index_gen<0,0> index_gen;
sl@0:   typedef detail::multi_array::extent_gen<0> extent_gen;
sl@0: }
sl@0: 
sl@0: 
sl@0: // boost::extents and boost::indices are now a part of the public
sl@0: // interface.  That way users don't necessarily have to create their 
sl@0: // own objects.  On the other hand, one may not want the overhead of 
sl@0: // object creation in small-memory environments.  Thus, the objects
sl@0: // can be left undefined by defining BOOST_MULTI_ARRAY_NO_GENERATORS 
sl@0: // before loading multi_array.hpp.
sl@0: #if !BOOST_MULTI_ARRAY_NO_GENERATORS
sl@0: namespace {
sl@0:   multi_array_types::extent_gen extents;
sl@0:   multi_array_types::index_gen indices;
sl@0: }
sl@0: #endif // BOOST_MULTI_ARRAY_NO_GENERATORS
sl@0: 
sl@0: namespace detail {
sl@0: namespace multi_array {
sl@0: 
sl@0: template <typename T, std::size_t NumDims>
sl@0: class sub_array;
sl@0: 
sl@0: template <typename T, std::size_t NumDims, typename TPtr = const T*>
sl@0: class const_sub_array;
sl@0: 
sl@0: template <typename T, typename TPtr, typename NumDims, typename Reference>
sl@0: class array_iterator;
sl@0: 
sl@0: template <typename T, std::size_t NumDims, typename TPtr = const T*>
sl@0: class const_multi_array_view;
sl@0: 
sl@0: template <typename T, std::size_t NumDims>
sl@0: class multi_array_view;
sl@0: 
sl@0: /////////////////////////////////////////////////////////////////////////
sl@0: // class interfaces
sl@0: /////////////////////////////////////////////////////////////////////////
sl@0: 
sl@0: class multi_array_base {
sl@0: public:
sl@0:   typedef multi_array_types::size_type size_type;
sl@0:   typedef multi_array_types::difference_type difference_type;
sl@0:   typedef multi_array_types::index index;
sl@0:   typedef multi_array_types::index_range index_range;
sl@0:   typedef multi_array_types::extent_range extent_range;
sl@0:   typedef multi_array_types::index_gen index_gen;
sl@0:   typedef multi_array_types::extent_gen extent_gen;
sl@0: };
sl@0: 
sl@0: //
sl@0: // value_accessor_n
sl@0: //  contains the routines for accessing elements from
sl@0: //  N-dimensional views.
sl@0: //
sl@0: template<typename T, std::size_t NumDims>
sl@0: class value_accessor_n : public multi_array_base {
sl@0:   typedef multi_array_base super_type;
sl@0: public:
sl@0:   typedef typename super_type::index index;
sl@0: 
sl@0:   // 
sl@0:   // public typedefs used by classes that inherit from this base
sl@0:   //
sl@0:   typedef T element;
sl@0:   typedef boost::multi_array<T,NumDims-1> value_type;
sl@0:   typedef sub_array<T,NumDims-1> reference;
sl@0:   typedef const_sub_array<T,NumDims-1> const_reference;
sl@0: 
sl@0: protected:
sl@0:   // used by array operator[] and iterators to get reference types.
sl@0:   template <typename Reference, typename TPtr>
sl@0:   Reference access(boost::type<Reference>,index idx,TPtr base,
sl@0:                    const size_type* extents,
sl@0:                    const index* strides,
sl@0:                    const index* index_bases) const {
sl@0: 
sl@0:     BOOST_ASSERT(idx - index_bases[0] >= 0);
sl@0:     BOOST_ASSERT(size_type(idx - index_bases[0]) < extents[0]);
sl@0:     // return a sub_array<T,NDims-1> proxy object
sl@0:     TPtr newbase = base + idx * strides[0];
sl@0:     return Reference(newbase,extents+1,strides+1,index_bases+1);
sl@0: 
sl@0:   }
sl@0: 
sl@0:   value_accessor_n() { }
sl@0:   ~value_accessor_n() { }
sl@0: };
sl@0: 
sl@0: 
sl@0: 
sl@0: //
sl@0: // value_accessor_one
sl@0: //  contains the routines for accessing reference elements from
sl@0: //  1-dimensional views.
sl@0: //
sl@0: template<typename T>
sl@0: class value_accessor_one : public multi_array_base {
sl@0:   typedef multi_array_base super_type;
sl@0: public:
sl@0:   typedef typename super_type::index index;
sl@0:   //
sl@0:   // public typedefs for use by classes that inherit it.
sl@0:   //
sl@0:   typedef T element;
sl@0:   typedef T value_type;
sl@0:   typedef T& reference;
sl@0:   typedef T const& const_reference;
sl@0: 
sl@0: protected:
sl@0:   // used by array operator[] and iterators to get reference types.
sl@0:   template <typename Reference, typename TPtr>
sl@0:   Reference access(boost::type<Reference>,index idx,TPtr base,
sl@0:                    const size_type* extents,
sl@0:                    const index* strides,
sl@0:                    const index* index_bases) const {
sl@0: 
sl@0:     ignore_unused_variable_warning(index_bases);
sl@0:     ignore_unused_variable_warning(extents);
sl@0:     BOOST_ASSERT(idx - index_bases[0] >= 0);
sl@0:     BOOST_ASSERT(size_type(idx - index_bases[0]) < extents[0]);
sl@0:     return *(base + idx * strides[0]);
sl@0:   }
sl@0: 
sl@0:   value_accessor_one() { }
sl@0:   ~value_accessor_one() { }
sl@0: };
sl@0: 
sl@0: 
sl@0: /////////////////////////////////////////////////////////////////////////
sl@0: // choose value accessor begins
sl@0: //
sl@0: 
sl@0: template <typename T, std::size_t NumDims>
sl@0: struct choose_value_accessor_n {
sl@0:   typedef value_accessor_n<T,NumDims> type;
sl@0: };
sl@0: 
sl@0: template <typename T>
sl@0: struct choose_value_accessor_one {
sl@0:   typedef value_accessor_one<T> type;
sl@0: };
sl@0: 
sl@0: template <typename T, typename NumDims>
sl@0: struct value_accessor_generator {
sl@0:     BOOST_STATIC_CONSTANT(std::size_t, dimensionality = NumDims::value);
sl@0:     
sl@0:   typedef typename
sl@0:   mpl::eval_if_c<(dimensionality == 1),
sl@0:                   choose_value_accessor_one<T>,
sl@0:                   choose_value_accessor_n<T,dimensionality>
sl@0:   >::type type;
sl@0: };
sl@0: 
sl@0: #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
sl@0: 
sl@0: struct eti_value_accessor
sl@0: {
sl@0:   typedef int index;
sl@0:   typedef int size_type;
sl@0:   typedef int element;
sl@0:   typedef int index_range;
sl@0:   typedef int value_type;
sl@0:   typedef int reference;
sl@0:   typedef int const_reference;
sl@0: };
sl@0:     
sl@0: template <>
sl@0: struct value_accessor_generator<int,int>
sl@0: {
sl@0:   typedef eti_value_accessor type;
sl@0: };
sl@0: 
sl@0: template <class T, class NumDims>
sl@0: struct associated_types
sl@0:   : mpl::aux::msvc_eti_base<
sl@0:         typename value_accessor_generator<T,NumDims>::type
sl@0:     >::type
sl@0: {};
sl@0: 
sl@0: template <>
sl@0: struct associated_types<int,int> : eti_value_accessor {};
sl@0: 
sl@0: #else
sl@0: 
sl@0: template <class T, class NumDims>
sl@0: struct associated_types
sl@0:   : value_accessor_generator<T,NumDims>::type
sl@0: {};
sl@0: 
sl@0: #endif
sl@0: 
sl@0: //
sl@0: // choose value accessor ends
sl@0: /////////////////////////////////////////////////////////////////////////
sl@0: 
sl@0: 
sl@0: 
sl@0: ////////////////////////////////////////////////////////////////////////
sl@0: // multi_array_base
sl@0: ////////////////////////////////////////////////////////////////////////
sl@0: template <typename T, std::size_t NumDims>
sl@0: class multi_array_impl_base
sl@0:   :
sl@0: #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
sl@0:       public mpl::aux::msvc_eti_base<
sl@0:           typename value_accessor_generator<T,mpl::size_t<NumDims> >::type
sl@0:        >::type
sl@0: #else
sl@0:       public value_accessor_generator<T,mpl::size_t<NumDims> >::type
sl@0: #endif 
sl@0: {
sl@0:   typedef associated_types<T,mpl::size_t<NumDims> > types;
sl@0: public:
sl@0:   typedef typename types::index index;
sl@0:   typedef typename types::size_type size_type;
sl@0:   typedef typename types::element element;
sl@0:   typedef typename types::index_range index_range;
sl@0:   typedef typename types::value_type value_type;
sl@0:   typedef typename types::reference reference;
sl@0:   typedef typename types::const_reference const_reference;
sl@0: 
sl@0:   template <std::size_t NDims>
sl@0:   struct subarray {
sl@0:     typedef boost::detail::multi_array::sub_array<T,NDims> type;
sl@0:   };
sl@0: 
sl@0:   template <std::size_t NDims>
sl@0:   struct const_subarray {
sl@0:     typedef boost::detail::multi_array::const_sub_array<T,NDims> type;
sl@0:   };
sl@0: 
sl@0:   template <std::size_t NDims>
sl@0:   struct array_view {
sl@0:     typedef boost::detail::multi_array::multi_array_view<T,NDims> type;
sl@0:   };
sl@0: 
sl@0:   template <std::size_t NDims>
sl@0:   struct const_array_view {
sl@0:   public:
sl@0:     typedef boost::detail::multi_array::const_multi_array_view<T,NDims> type;
sl@0:   };
sl@0: 
sl@0:   //
sl@0:   // iterator support
sl@0:   //
sl@0:   typedef array_iterator<T,T*,mpl::size_t<NumDims>,reference> iterator;
sl@0:   typedef array_iterator<T,T const*,mpl::size_t<NumDims>,const_reference> const_iterator;
sl@0: 
sl@0:   typedef ::boost::reverse_iterator<iterator> reverse_iterator;
sl@0:   typedef ::boost::reverse_iterator<const_iterator> const_reverse_iterator;
sl@0: 
sl@0:   BOOST_STATIC_CONSTANT(std::size_t, dimensionality = NumDims);
sl@0: protected:
sl@0: 
sl@0:   multi_array_impl_base() { }
sl@0:   ~multi_array_impl_base() { }
sl@0: 
sl@0:   // Used by operator() in our array classes
sl@0:   template <typename Reference, typename IndexList, typename TPtr>
sl@0:   Reference access_element(boost::type<Reference>,
sl@0:                            const IndexList& indices,
sl@0:                            TPtr base,
sl@0:                            const size_type* extents,
sl@0:                            const index* strides,
sl@0:                            const index* index_bases) const {
sl@0: 
sl@0:     ignore_unused_variable_warning(index_bases);
sl@0:     ignore_unused_variable_warning(extents);
sl@0: #if !defined(NDEBUG) && !defined(BOOST_DISABLE_ASSERTS)
sl@0:     for (size_type i = 0; i != NumDims; ++i) {
sl@0:       BOOST_ASSERT(indices[i] - index_bases[i] >= 0);
sl@0:       BOOST_ASSERT(size_type(indices[i] - index_bases[i]) < extents[i]);
sl@0:     }
sl@0: #endif
sl@0: 
sl@0:     index offset = 0;
sl@0:     for (size_type n = 0; n != NumDims; ++n) 
sl@0:       offset += indices[n] * strides[n];
sl@0:     
sl@0:     return base[offset];
sl@0:   }
sl@0: 
sl@0:   template <typename StrideList, typename ExtentList>
sl@0:   void compute_strides(StrideList& stride_list, ExtentList& extent_list,
sl@0:                        const general_storage_order<NumDims>& storage)
sl@0:   {
sl@0:     // invariant: stride = the stride for dimension n
sl@0:     index stride = 1;
sl@0:     for (size_type n = 0; n != NumDims; ++n) {
sl@0:       index stride_sign = +1;
sl@0:       
sl@0:       if (!storage.ascending(storage.ordering(n)))
sl@0:         stride_sign = -1;
sl@0:       
sl@0:       // The stride for this dimension is the product of the
sl@0:       // lengths of the ranks minor to it.
sl@0:       stride_list[storage.ordering(n)] = stride * stride_sign;
sl@0:       
sl@0:       stride *= extent_list[storage.ordering(n)];
sl@0:     } 
sl@0:   }
sl@0: 
sl@0:   // This calculates the offset to the array base pointer due to:
sl@0:   // 1. dimensions stored in descending order
sl@0:   // 2. non-zero dimension index bases
sl@0:   template <typename StrideList, typename ExtentList, typename BaseList>
sl@0:   index
sl@0:   calculate_origin_offset(const StrideList& stride_list,
sl@0:                           const ExtentList& extent_list,
sl@0:                           const general_storage_order<NumDims>& storage,
sl@0:                           const BaseList& index_base_list)
sl@0:   {
sl@0:     return
sl@0:       calculate_descending_dimension_offset(stride_list,extent_list,
sl@0:                                             storage) +
sl@0:       calculate_indexing_offset(stride_list,index_base_list);
sl@0:   }
sl@0: 
sl@0:   // This calculates the offset added to the base pointer that are
sl@0:   // caused by descending dimensions
sl@0:   template <typename StrideList, typename ExtentList>
sl@0:   index
sl@0:   calculate_descending_dimension_offset(const StrideList& stride_list,
sl@0:                                 const ExtentList& extent_list,
sl@0:                                 const general_storage_order<NumDims>& storage)
sl@0:   {
sl@0:     index offset = 0;
sl@0:     if (!storage.all_dims_ascending()) 
sl@0:       for (size_type n = 0; n != NumDims; ++n)
sl@0:         if (!storage.ascending(n))
sl@0:           offset -= (extent_list[n] - 1) * stride_list[n];
sl@0: 
sl@0:     return offset;
sl@0:   }
sl@0: 
sl@0:   // This is used to reindex array_views, which are no longer
sl@0:   // concerned about storage order (specifically, whether dimensions
sl@0:   // are ascending or descending) since the viewed array handled it.
sl@0: 
sl@0:   template <typename StrideList, typename BaseList>
sl@0:   index
sl@0:   calculate_indexing_offset(const StrideList& stride_list,
sl@0:                           const BaseList& index_base_list)
sl@0:   {
sl@0:     index offset = 0;
sl@0:     for (size_type n = 0; n != NumDims; ++n)
sl@0:         offset -= stride_list[n] * index_base_list[n];
sl@0:     return offset;
sl@0:   }
sl@0: 
sl@0:   // Slicing using an index_gen.
sl@0:   // Note that populating an index_gen creates a type that encodes
sl@0:   // both the number of dimensions in the current Array (NumDims), and 
sl@0:   // the Number of dimensions for the resulting view.  This allows the 
sl@0:   // compiler to fail if the dimensions aren't completely accounted
sl@0:   // for.  For reasons unbeknownst to me, a BOOST_STATIC_ASSERT
sl@0:   // within the member function template does not work. I should add a 
sl@0:   // note to the documentation specifying that you get a damn ugly
sl@0:   // error message if you screw up in your slicing code.
sl@0:   template <typename ArrayRef, int NDims, typename TPtr>
sl@0:   ArrayRef
sl@0:   generate_array_view(boost::type<ArrayRef>,
sl@0:                       const boost::detail::multi_array::
sl@0:                       index_gen<NumDims,NDims>& indices,
sl@0:                       const size_type* extents,
sl@0:                       const index* strides,
sl@0:                       const index* index_bases,
sl@0:                       TPtr base) const {
sl@0: 
sl@0:     boost::array<index,NDims> new_strides;
sl@0:     boost::array<index,NDims> new_extents;
sl@0: 
sl@0:     index offset = 0;
sl@0:     size_type dim = 0;
sl@0:     for (size_type n = 0; n != NumDims; ++n) {
sl@0:       const index default_start = index_bases[n];
sl@0:       const index default_finish = default_start+extents[n];
sl@0:       const index_range& current_range = indices.ranges_[n];
sl@0:       index start = current_range.get_start(default_start);
sl@0:       index finish = current_range.get_finish(default_finish);
sl@0:       index index_factor = current_range.stride();
sl@0:       index len = (finish - start + (index_factor - 1)) / index_factor;
sl@0: 
sl@0:       BOOST_ASSERT(index_bases[n] <= start &&
sl@0:                    start <= index_bases[n]+index(extents[n]));
sl@0:       BOOST_ASSERT(index_bases[n] <= finish &&
sl@0:                    finish <= index_bases[n]+index(extents[n]));
sl@0:       BOOST_ASSERT(index_factor > 0);
sl@0: 
sl@0:       // the array data pointer is modified to account for non-zero
sl@0:       // bases during slicing (see [Garcia] for the math involved)
sl@0:       offset += start * strides[n];
sl@0: 
sl@0:       if (!current_range.is_degenerate()) {
sl@0: 
sl@0:         // The index_factor for each dimension is included into the
sl@0:         // strides for the array_view (see [Garcia] for the math involved).
sl@0:         new_strides[dim] = index_factor * strides[n];
sl@0:         
sl@0:         // calculate new extents
sl@0:         new_extents[dim] = len;
sl@0:         ++dim;
sl@0:       }
sl@0:     }
sl@0:     BOOST_ASSERT(dim == NDims);
sl@0: 
sl@0:     return
sl@0:       ArrayRef(base+offset,
sl@0:                new_extents,
sl@0:                new_strides);
sl@0:   }
sl@0:                      
sl@0: 
sl@0: };
sl@0: 
sl@0: } // namespace multi_array
sl@0: } // namespace detail
sl@0: 
sl@0: } // namespace boost
sl@0: 
sl@0: #endif // BASE_RG071801_HPP