boost/multi_array/iterator.hpp
// Copyright 2002 The Trustees of Indiana University.
// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
// Boost.MultiArray Library
// Authors: Ronald Garcia
// Jeremy Siek
// Andrew Lumsdaine
// See http://www.boost.org/libs/multi_array for documentation.
#ifndef ITERATOR_RG071801_HPP
#define ITERATOR_RG071801_HPP
//
// iterator.hpp - implementation of iterators for the
// multi-dimensional array class
//
#include "boost/multi_array/base.hpp"
#include "boost/iterator/iterator_facade.hpp"
#include "boost/mpl/aux_/msvc_eti_base.hpp"
#include <algorithm>
#include <cstddef>
#include <iterator>
namespace boost {
namespace detail {
namespace multi_array {
/////////////////////////////////////////////////////////////////////////
// iterator components
/////////////////////////////////////////////////////////////////////////
template <class T>
struct operator_arrow_proxy
{
operator_arrow_proxy(T const& px) : value_(px) {}
T* operator->() const { return &value_; }
// This function is needed for MWCW and BCC, which won't call operator->
// again automatically per 13.3.1.2 para 8
operator T*() const { return &value_; }
mutable T value_;
};
template <typename T, typename TPtr, typename NumDims, typename Reference>
class array_iterator;
template <typename T, typename TPtr, typename NumDims, typename Reference>
class array_iterator
: public
iterator_facade<
array_iterator<T,TPtr,NumDims,Reference>
, typename associated_types<T,NumDims>::value_type
, boost::random_access_traversal_tag
, Reference
>
, private
#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
mpl::aux::msvc_eti_base<typename
#endif
value_accessor_generator<T,NumDims>::type
#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
>::type
#endif
{
friend class iterator_core_access;
typedef detail::multi_array::associated_types<T,NumDims> access_t;
typedef iterator_facade<
array_iterator<T,TPtr,NumDims,Reference>
, typename detail::multi_array::associated_types<T,NumDims>::value_type
, boost::random_access_traversal_tag
, Reference
> facade_type;
typedef typename access_t::index index;
typedef typename access_t::size_type size_type;
#ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
template <typename, typename, typename, typename>
friend class array_iterator;
#else
public:
#endif
index idx_;
TPtr base_;
const size_type* extents_;
const index* strides_;
const index* index_base_;
public:
// Typedefs to circumvent ambiguities between parent classes
typedef typename facade_type::reference reference;
typedef typename facade_type::value_type value_type;
typedef typename facade_type::difference_type difference_type;
array_iterator() {}
array_iterator(index idx, TPtr base, const size_type* extents,
const index* strides,
const index* index_base) :
idx_(idx), base_(base), extents_(extents),
strides_(strides), index_base_(index_base) { }
template <typename OPtr, typename ORef>
array_iterator(
const array_iterator<T,OPtr,NumDims,ORef>& rhs
, typename boost::enable_if_convertible<OPtr,TPtr>::type* = 0
)
: idx_(rhs.idx_), base_(rhs.base_), extents_(rhs.extents_),
strides_(rhs.strides_), index_base_(rhs.index_base_) { }
// RG - we make our own operator->
operator_arrow_proxy<reference>
operator->() const
{
return operator_arrow_proxy<reference>(this->dereference());
}
reference dereference() const
{
typedef typename value_accessor_generator<T,NumDims>::type accessor;
return accessor::access(boost::type<reference>(),
idx_,
base_,
extents_,
strides_,
index_base_);
}
void increment() { ++idx_; }
void decrement() { --idx_; }
template <class IteratorAdaptor>
bool equal(IteratorAdaptor& rhs) const {
const std::size_t N = NumDims::value;
return (idx_ == rhs.idx_) &&
(base_ == rhs.base_) &&
( (extents_ == rhs.extents_) ||
std::equal(extents_,extents_+N,rhs.extents_) ) &&
( (strides_ == rhs.strides_) ||
std::equal(strides_,strides_+N,rhs.strides_) ) &&
( (index_base_ == rhs.index_base_) ||
std::equal(index_base_,index_base_+N,rhs.index_base_) );
}
template <class DifferenceType>
void advance(DifferenceType n) {
idx_ += n;
}
template <class IteratorAdaptor>
typename facade_type::difference_type
distance_to(IteratorAdaptor& rhs) const {
return rhs.idx_ - idx_;
}
};
} // namespace multi_array
} // namespace detail
} // namespace boost
#endif // ITERATOR_RG071801_HPP