// Boost.Range library | |
// | |
// Copyright Neil Groves 2009. 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) | |
// | |
// | |
// For more information, see http://www.boost.org/libs/range/ | |
// | |
#ifndef BOOST_RANGE_DETAIL_JOIN_ITERATOR_HPP_INCLUDED | |
#define BOOST_RANGE_DETAIL_JOIN_ITERATOR_HPP_INCLUDED | |
#include <iterator> | |
#include <boost/assert.hpp> | |
#include <boost/iterator/iterator_traits.hpp> | |
#include <boost/iterator/iterator_facade.hpp> | |
#include <boost/range/begin.hpp> | |
#include <boost/range/end.hpp> | |
#include <boost/range/empty.hpp> | |
#include <boost/range/detail/demote_iterator_traversal_tag.hpp> | |
#include <boost/range/value_type.hpp> | |
#include <boost/utility.hpp> | |
namespace boost | |
{ | |
namespace range_detail | |
{ | |
template<typename Iterator1, typename Iterator2> | |
struct join_iterator_link | |
{ | |
public: | |
join_iterator_link(Iterator1 last1, Iterator2 first2) | |
: last1(last1) | |
, first2(first2) | |
{ | |
} | |
Iterator1 last1; | |
Iterator2 first2; | |
private: | |
join_iterator_link() /* = delete */ ; | |
}; | |
class join_iterator_begin_tag {}; | |
class join_iterator_end_tag {}; | |
template<typename Iterator1 | |
, typename Iterator2 | |
, typename Reference | |
> | |
class join_iterator_union | |
{ | |
public: | |
typedef Iterator1 iterator1_t; | |
typedef Iterator2 iterator2_t; | |
join_iterator_union() {} | |
join_iterator_union(unsigned int /*selected*/, const iterator1_t& it1, const iterator2_t& it2) : m_it1(it1), m_it2(it2) {} | |
iterator1_t& it1() { return m_it1; } | |
const iterator1_t& it1() const { return m_it1; } | |
iterator2_t& it2() { return m_it2; } | |
const iterator2_t& it2() const { return m_it2; } | |
Reference dereference(unsigned int selected) const | |
{ | |
return selected ? *m_it2 : *m_it1; | |
} | |
bool equal(const join_iterator_union& other, unsigned int selected) const | |
{ | |
return selected | |
? m_it2 == other.m_it2 | |
: m_it1 == other.m_it1; | |
} | |
private: | |
iterator1_t m_it1; | |
iterator2_t m_it2; | |
}; | |
template<class Iterator, class Reference> | |
class join_iterator_union<Iterator, Iterator, Reference> | |
{ | |
public: | |
typedef Iterator iterator1_t; | |
typedef Iterator iterator2_t; | |
join_iterator_union() {} | |
join_iterator_union(unsigned int selected, const iterator1_t& it1, const iterator2_t& it2) | |
: m_it(selected ? it2 : it1) | |
{ | |
} | |
iterator1_t& it1() { return m_it; } | |
const iterator1_t& it1() const { return m_it; } | |
iterator2_t& it2() { return m_it; } | |
const iterator2_t& it2() const { return m_it; } | |
Reference dereference(unsigned int) const | |
{ | |
return *m_it; | |
} | |
bool equal(const join_iterator_union& other, unsigned int selected) const | |
{ | |
return m_it == other.m_it; | |
} | |
private: | |
iterator1_t m_it; | |
}; | |
template<typename Iterator1 | |
, typename Iterator2 | |
, typename ValueType = typename iterator_value<Iterator1>::type | |
, typename Reference = typename iterator_reference<Iterator1>::type | |
, typename Traversal = typename demote_iterator_traversal_tag< | |
typename iterator_traversal<Iterator1>::type | |
, typename iterator_traversal<Iterator2>::type>::type | |
> | |
class join_iterator | |
: public iterator_facade<join_iterator<Iterator1,Iterator2,ValueType,Reference,Traversal>, ValueType, Traversal, Reference> | |
{ | |
typedef join_iterator_link<Iterator1, Iterator2> link_t; | |
typedef join_iterator_union<Iterator1, Iterator2, Reference> iterator_union; | |
public: | |
typedef Iterator1 iterator1_t; | |
typedef Iterator2 iterator2_t; | |
join_iterator() | |
: m_section(0u) | |
, m_it(0u, iterator1_t(), iterator2_t()) | |
, m_link(link_t(iterator1_t(), iterator2_t())) | |
{} | |
join_iterator(unsigned int section, Iterator1 current1, Iterator1 last1, Iterator2 first2, Iterator2 current2) | |
: m_section(section) | |
, m_it(section, current1, current2) | |
, m_link(link_t(last1, first2)) | |
{ | |
} | |
template<typename Range1, typename Range2> | |
join_iterator(Range1& r1, Range2& r2, join_iterator_begin_tag) | |
: m_section(boost::empty(r1) ? 1u : 0u) | |
, m_it(boost::empty(r1) ? 1u : 0u, boost::begin(r1), boost::begin(r2)) | |
, m_link(link_t(boost::end(r1), boost::begin(r2))) | |
{ | |
} | |
template<typename Range1, typename Range2> | |
join_iterator(const Range1& r1, const Range2& r2, join_iterator_begin_tag) | |
: m_section(boost::empty(r1) ? 1u : 0u) | |
, m_it(boost::empty(r1) ? 1u : 0u, boost::const_begin(r1), boost::const_begin(r2)) | |
, m_link(link_t(boost::const_end(r1), boost::const_begin(r2))) | |
{ | |
} | |
template<typename Range1, typename Range2> | |
join_iterator(Range1& r1, Range2& r2, join_iterator_end_tag) | |
: m_section(1u) | |
, m_it(1u, boost::end(r1), boost::end(r2)) | |
, m_link(link_t(boost::end(r1), boost::begin(r2))) | |
{ | |
} | |
template<typename Range1, typename Range2> | |
join_iterator(const Range1& r1, const Range2& r2, join_iterator_end_tag) | |
: m_section(1u) | |
, m_it(1u, boost::const_end(r1), boost::const_end(r2)) | |
, m_link(link_t(boost::const_end(r1), boost::const_begin(r2))) | |
{ | |
} | |
private: | |
void increment() | |
{ | |
if (m_section) | |
++m_it.it2(); | |
else | |
{ | |
++m_it.it1(); | |
if (m_it.it1() == m_link.last1) | |
{ | |
m_it.it2() = m_link.first2; | |
m_section = 1u; | |
} | |
} | |
} | |
void decrement() | |
{ | |
if (m_section) | |
{ | |
if (m_it.it2() == m_link.first2) | |
{ | |
m_it.it1() = boost::prior(m_link.last1); | |
m_section = 0u; | |
} | |
else | |
--m_it.it2(); | |
} | |
else | |
--m_it.it1(); | |
} | |
typename join_iterator::reference dereference() const | |
{ | |
return m_it.dereference(m_section); | |
} | |
bool equal(const join_iterator& other) const | |
{ | |
return m_section == other.m_section | |
&& m_it.equal(other.m_it, m_section); | |
} | |
void advance(typename join_iterator::difference_type offset) | |
{ | |
if (m_section) | |
advance_from_range2(offset); | |
else | |
advance_from_range1(offset); | |
} | |
typename join_iterator::difference_type distance_to(const join_iterator& other) const | |
{ | |
typename join_iterator::difference_type result; | |
if (m_section) | |
{ | |
if (other.m_section) | |
result = other.m_it.it2() - m_it.it2(); | |
else | |
{ | |
result = (m_link.first2 - m_it.it2()) | |
+ (other.m_it.it1() - m_link.last1); | |
BOOST_ASSERT( result <= 0 ); | |
} | |
} | |
else | |
{ | |
if (other.m_section) | |
{ | |
result = (m_link.last1 - m_it.it1()) | |
+ (other.m_it.it2() - m_link.first2); | |
} | |
else | |
result = other.m_it.it1() - m_it.it1(); | |
} | |
return result; | |
} | |
void advance_from_range2(typename join_iterator::difference_type offset) | |
{ | |
typedef typename join_iterator::difference_type difference_t; | |
BOOST_ASSERT( m_section == 1u ); | |
if (offset < 0) | |
{ | |
difference_t r2_dist = m_link.first2 - m_it.it2(); | |
BOOST_ASSERT( r2_dist <= 0 ); | |
if (offset >= r2_dist) | |
std::advance(m_it.it2(), offset); | |
else | |
{ | |
difference_t r1_dist = offset - r2_dist; | |
BOOST_ASSERT( r1_dist <= 0 ); | |
m_it.it1() = m_link.last1 + r1_dist; | |
m_section = 0u; | |
} | |
} | |
else | |
std::advance(m_it.it2(), offset); | |
} | |
void advance_from_range1(typename join_iterator::difference_type offset) | |
{ | |
typedef typename join_iterator::difference_type difference_t; | |
BOOST_ASSERT( m_section == 0u ); | |
if (offset > 0) | |
{ | |
difference_t r1_dist = m_link.last1 - m_it.it1(); | |
BOOST_ASSERT( r1_dist >= 0 ); | |
if (offset < r1_dist) | |
std::advance(m_it.it1(), offset); | |
else | |
{ | |
difference_t r2_dist = offset - r1_dist; | |
BOOST_ASSERT( r2_dist >= 0 ); | |
m_it.it2() = m_link.first2 + r2_dist; | |
m_section = 1u; | |
} | |
} | |
else | |
std::advance(m_it.it1(), offset); | |
} | |
unsigned int m_section; | |
iterator_union m_it; | |
link_t m_link; | |
friend class ::boost::iterator_core_access; | |
}; | |
} // namespace range_detail | |
} // namespace boost | |
#endif // include guard |