3 // Copyright Neil Groves & Thorsten Ottosen & Pavol Droba 2003-2004.
4 // Use, modification and distribution is subject to the Boost Software
5 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
6 // http://www.boost.org/LICENSE_1_0.txt)
8 // For more information, see http://www.boost.org/libs/range/
11 // 'michel' reported Trac 9072 which included a patch for allowing references
14 #ifndef BOOST_RANGE_ITERATOR_RANGE_CORE_HPP_INCLUDED
15 #define BOOST_RANGE_ITERATOR_RANGE_CORE_HPP_INCLUDED
17 #include <boost/config.hpp> // Define __STL_CONFIG_H, if appropriate.
18 #include <boost/detail/workaround.hpp>
20 #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1500))
21 #pragma warning( push )
22 #pragma warning( disable : 4996 )
25 #include <boost/assert.hpp>
26 #include <boost/iterator/iterator_traits.hpp>
27 #include <boost/iterator/iterator_facade.hpp>
28 #include <boost/mpl/if.hpp>
29 #include <boost/mpl/not.hpp>
30 #include <boost/mpl/or.hpp>
31 #include <boost/type_traits/is_abstract.hpp>
32 #include <boost/type_traits/is_array.hpp>
33 #include <boost/type_traits/is_base_and_derived.hpp>
34 #include <boost/type_traits/is_convertible.hpp>
35 #include <boost/type_traits/is_function.hpp>
36 #include <boost/type_traits/is_pointer.hpp>
37 #include <boost/type_traits/is_same.hpp>
38 #include <boost/range/functions.hpp>
39 #include <boost/range/iterator.hpp>
40 #include <boost/range/difference_type.hpp>
41 #include <boost/range/has_range_iterator.hpp>
42 #include <boost/range/algorithm/equal.hpp>
43 #include <boost/range/detail/safe_bool.hpp>
44 #include <boost/utility/enable_if.hpp>
50 Defines the \c iterator_class and related functions.
51 \c iterator_range is a simple wrapper of iterator pair idiom. It provides
52 a rich subset of Container interface.
58 namespace iterator_range_detail
61 // The functions adl_begin and adl_end are implemented in a separate
64 template<class IteratorT>
65 struct iterator_range_impl {
66 template< class ForwardRange >
67 static IteratorT adl_begin( ForwardRange& r )
69 return IteratorT( boost::begin( r ) );
72 template< class ForwardRange >
73 static IteratorT adl_end( ForwardRange& r )
75 return IteratorT( boost::end( r ) );
79 template< class Left, class Right >
80 inline bool less_than( const Left& l, const Right& r )
82 return std::lexicographical_compare( boost::begin(l),
88 template< class Left, class Right >
89 inline bool greater_than( const Left& l, const Right& r )
91 return iterator_range_detail::less_than(r,l);
94 template< class Left, class Right >
95 inline bool less_or_equal_than( const Left& l, const Right& r )
97 return !iterator_range_detail::less_than(r,l);
100 template< class Left, class Right >
101 inline bool greater_or_equal_than( const Left& l, const Right& r )
103 return !iterator_range_detail::less_than(l,r);
106 // This version is maintained since it is used in other boost libraries
107 // such as Boost.Assign
108 template< class Left, class Right >
109 inline bool equal(const Left& l, const Right& r)
111 return boost::equal(l, r);
118 struct const_range_tag
122 struct iterator_range_tag
126 typedef char (&incrementable_t)[1];
127 typedef char (&bidirectional_t)[2];
128 typedef char (&random_access_t)[3];
130 incrementable_t test_traversal_tag(boost::incrementable_traversal_tag);
131 bidirectional_t test_traversal_tag(boost::bidirectional_traversal_tag);
132 random_access_t test_traversal_tag(boost::random_access_traversal_tag);
134 template<std::size_t S>
135 struct pure_iterator_traversal_impl
137 typedef boost::incrementable_traversal_tag type;
141 struct pure_iterator_traversal_impl<sizeof(bidirectional_t)>
143 typedef boost::bidirectional_traversal_tag type;
147 struct pure_iterator_traversal_impl<sizeof(random_access_t)>
149 typedef boost::random_access_traversal_tag type;
152 template<typename IteratorT>
153 struct pure_iterator_traversal
156 BOOST_DEDUCED_TYPENAME iterator_traversal<IteratorT>::type
158 BOOST_STATIC_CONSTANT(
160 traversal_i = sizeof(iterator_range_detail::test_traversal_tag((traversal_t())))
163 BOOST_DEDUCED_TYPENAME pure_iterator_traversal_impl<traversal_i>::type
167 template<class IteratorT, class TraversalTag>
168 class iterator_range_base
169 : public iterator_range_tag
171 typedef range_detail::safe_bool<
172 IteratorT iterator_range_base<IteratorT, TraversalTag>::*
175 typedef iterator_range_base<IteratorT, TraversalTag> type;
178 typedef iterator_range_impl<IteratorT> impl;
181 typedef BOOST_DEDUCED_TYPENAME
182 safe_bool_t::unspecified_bool_type unspecified_bool_type;
184 typedef BOOST_DEDUCED_TYPENAME
185 iterator_value<IteratorT>::type value_type;
187 typedef BOOST_DEDUCED_TYPENAME
188 iterator_difference<IteratorT>::type difference_type;
190 typedef std::size_t size_type; // note: must be unsigned
192 // Needed because value-type is the same for
193 // const and non-const iterators
194 typedef BOOST_DEDUCED_TYPENAME
195 iterator_reference<IteratorT>::type reference;
197 //! const_iterator type
199 There is no distinction between const_iterator and iterator.
200 These typedefs are provides to fulfill container interface
202 typedef IteratorT const_iterator;
204 typedef IteratorT iterator;
207 iterator_range_base()
213 template<class Iterator>
214 iterator_range_base(Iterator Begin, Iterator End)
221 IteratorT begin() const
226 IteratorT end() const
233 return m_Begin == m_End;
236 operator unspecified_bool_type() const
238 return safe_bool_t::to_unspecified_bool(
239 m_Begin != m_End, &iterator_range_base::m_Begin);
242 bool operator!() const
247 bool equal(const iterator_range_base& r) const
249 return m_Begin == r.m_Begin && m_End == r.m_End;
252 reference front() const
254 BOOST_ASSERT(!empty());
260 BOOST_ASSERT(!empty());
264 void drop_front(difference_type n)
266 BOOST_ASSERT(n >= difference_type());
267 std::advance(this->m_Begin, n);
271 void pop_front() { drop_front(); }
274 template<class Iterator>
275 void assign(Iterator first, Iterator last)
281 template<class SinglePassRange>
282 void assign(const SinglePassRange& r)
284 m_Begin = impl::adl_begin(r);
285 m_End = impl::adl_end(r);
288 template<class SinglePassRange>
289 void assign(SinglePassRange& r)
291 m_Begin = impl::adl_begin(r);
292 m_End = impl::adl_end(r);
299 template<class IteratorT>
300 class iterator_range_base<IteratorT, bidirectional_traversal_tag>
301 : public iterator_range_base<IteratorT, incrementable_traversal_tag>
303 typedef iterator_range_base<IteratorT, incrementable_traversal_tag> base_type;
306 iterator_range_base()
310 template<class Iterator>
311 iterator_range_base(Iterator first, Iterator last)
312 : base_type(first, last)
317 typedef BOOST_DEDUCED_TYPENAME base_type::difference_type difference_type;
318 typedef BOOST_DEDUCED_TYPENAME base_type::reference reference;
320 reference back() const
322 BOOST_ASSERT(!this->empty());
323 return *boost::prior(this->m_End);
328 BOOST_ASSERT(!this->empty());
332 void drop_back(difference_type n)
334 BOOST_ASSERT(n >= difference_type());
335 std::advance(this->m_End, -n);
339 void pop_back() { drop_back(); }
342 template<class IteratorT>
343 class iterator_range_base<IteratorT, random_access_traversal_tag>
344 : public iterator_range_base<IteratorT, bidirectional_traversal_tag>
346 typedef iterator_range_base<
347 IteratorT, bidirectional_traversal_tag> base_type;
350 typedef BOOST_DEDUCED_TYPENAME
354 BOOST_DEDUCED_TYPENAME base_type::value_type
357 BOOST_DEDUCED_TYPENAME base_type::value_type
360 BOOST_DEDUCED_TYPENAME base_type::value_type
363 BOOST_DEDUCED_TYPENAME base_type::reference,
364 BOOST_DEDUCED_TYPENAME base_type::value_type
365 >::type abstract_value_type;
368 // typedef these here to reduce verbiage in the implementation of this
370 typedef BOOST_DEDUCED_TYPENAME base_type::difference_type difference_type;
371 typedef BOOST_DEDUCED_TYPENAME base_type::size_type size_type;
372 typedef BOOST_DEDUCED_TYPENAME base_type::reference reference;
375 iterator_range_base()
379 template<class Iterator>
380 iterator_range_base(Iterator first, Iterator last)
381 : base_type(first, last)
386 reference operator[](difference_type at) const
388 BOOST_ASSERT(at >= 0);
389 BOOST_ASSERT(static_cast<typename base_type::size_type>(at) < size());
390 return this->m_Begin[at];
394 // When storing transform iterators, operator[]()
395 // fails because it returns by reference. Therefore
396 // operator()() is provided for these cases.
398 abstract_value_type operator()(difference_type at) const
400 BOOST_ASSERT(at >= 0);
401 BOOST_ASSERT(static_cast<typename base_type::size_type>(at) < size());
402 return this->m_Begin[at];
405 BOOST_DEDUCED_TYPENAME base_type::size_type size() const
407 return this->m_End - this->m_Begin;
413 // iterator range template class -----------------------------------------//
415 //! iterator_range class
417 An \c iterator_range delimits a range in a sequence by beginning and ending iterators.
418 An iterator_range can be passed to an algorithm which requires a sequence as an input.
419 For example, the \c toupper() function may be used most frequently on strings,
420 but can also be used on iterator_ranges:
423 boost::tolower( find( s, "UPPERCASE STRING" ) );
426 Many algorithms working with sequences take a pair of iterators,
427 delimiting a working range, as an arguments. The \c iterator_range class is an
428 encapsulation of a range identified by a pair of iterators.
429 It provides a collection interface,
430 so it is possible to pass an instance to an algorithm requiring a collection as an input.
432 template<class IteratorT>
434 : public iterator_range_detail::iterator_range_base<
436 BOOST_DEDUCED_TYPENAME iterator_range_detail::pure_iterator_traversal<IteratorT>::type
439 typedef iterator_range_detail::iterator_range_base<
441 BOOST_DEDUCED_TYPENAME iterator_range_detail::pure_iterator_traversal<IteratorT>::type
444 template<class Source>
445 struct is_compatible_range_
447 BOOST_DEDUCED_TYPENAME mpl::eval_if<
448 has_range_iterator<Source>,
449 range_iterator<Source>,
452 BOOST_DEDUCED_TYPENAME base_type::iterator
457 template<class Source>
458 struct is_compatible_range
463 BOOST_DEDUCED_TYPENAME base_type::iterator
466 is_compatible_range_<Source>
472 typedef iterator_range_detail::iterator_range_impl<IteratorT> impl;
475 typedef iterator_range<IteratorT> type;
481 template<class Iterator>
482 iterator_range(Iterator first, Iterator last)
483 : base_type(first, last)
487 template<class SinglePassRange>
489 const SinglePassRange& r,
490 BOOST_DEDUCED_TYPENAME ::boost::enable_if<
491 is_compatible_range<const SinglePassRange>
494 : base_type(impl::adl_begin(r), impl::adl_end(r))
498 template<class SinglePassRange>
501 BOOST_DEDUCED_TYPENAME ::boost::enable_if<
502 is_compatible_range<SinglePassRange>
505 : base_type(impl::adl_begin(r), impl::adl_end(r))
509 template<class SinglePassRange>
510 iterator_range(const SinglePassRange& r,
511 iterator_range_detail::const_range_tag)
512 : base_type(impl::adl_begin(r), impl::adl_end(r))
516 template<class SinglePassRange>
517 iterator_range(SinglePassRange& r,
518 iterator_range_detail::range_tag)
519 : base_type(impl::adl_begin(r), impl::adl_end(r))
523 template<class Iterator>
524 iterator_range& operator=(const iterator_range<Iterator>& other)
526 this->assign(other.begin(), other.end());
530 template<class Iterator>
531 iterator_range& operator=(iterator_range<Iterator>& other)
533 this->assign(other.begin(), other.end());
537 template<class SinglePassRange>
538 iterator_range& operator=(SinglePassRange& r)
544 template<class SinglePassRange>
545 iterator_range& operator=(const SinglePassRange& r)
551 iterator_range& advance_begin(
552 BOOST_DEDUCED_TYPENAME base_type::difference_type n)
554 std::advance(this->m_Begin, n);
558 iterator_range& advance_end(
559 BOOST_DEDUCED_TYPENAME base_type::difference_type n)
561 std::advance(this->m_End, n);
567 // Allow subclasses an easy way to access the
570 typedef iterator_range iterator_range_;
573 // iterator range free-standing operators ---------------------------//
575 /////////////////////////////////////////////////////////////////////
576 // comparison operators
577 /////////////////////////////////////////////////////////////////////
579 template< class IteratorT, class ForwardRange >
580 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
581 mpl::not_<is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
584 operator==( const ForwardRange& l, const iterator_range<IteratorT>& r )
586 return boost::equal( l, r );
589 template< class IteratorT, class ForwardRange >
590 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
591 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
594 operator!=( const ForwardRange& l, const iterator_range<IteratorT>& r )
596 return !boost::equal( l, r );
599 template< class IteratorT, class ForwardRange >
600 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
601 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
604 operator<( const ForwardRange& l, const iterator_range<IteratorT>& r )
606 return iterator_range_detail::less_than( l, r );
609 template< class IteratorT, class ForwardRange >
610 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
611 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
614 operator<=( const ForwardRange& l, const iterator_range<IteratorT>& r )
616 return iterator_range_detail::less_or_equal_than( l, r );
619 template< class IteratorT, class ForwardRange >
620 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
621 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
624 operator>( const ForwardRange& l, const iterator_range<IteratorT>& r )
626 return iterator_range_detail::greater_than( l, r );
629 template< class IteratorT, class ForwardRange >
630 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
631 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
634 operator>=( const ForwardRange& l, const iterator_range<IteratorT>& r )
636 return iterator_range_detail::greater_or_equal_than( l, r );
639 #ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
641 template< class Iterator1T, class Iterator2T >
643 operator==( const iterator_range<Iterator1T>& l, const iterator_range<Iterator2T>& r )
645 return boost::equal( l, r );
648 template< class IteratorT, class ForwardRange >
649 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
650 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
653 operator==( const iterator_range<IteratorT>& l, const ForwardRange& r )
655 return boost::equal( l, r );
659 template< class Iterator1T, class Iterator2T >
661 operator!=( const iterator_range<Iterator1T>& l, const iterator_range<Iterator2T>& r )
663 return !boost::equal( l, r );
666 template< class IteratorT, class ForwardRange >
667 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
668 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
671 operator!=( const iterator_range<IteratorT>& l, const ForwardRange& r )
673 return !boost::equal( l, r );
677 template< class Iterator1T, class Iterator2T >
679 operator<( const iterator_range<Iterator1T>& l, const iterator_range<Iterator2T>& r )
681 return iterator_range_detail::less_than( l, r );
684 template< class IteratorT, class ForwardRange >
685 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
686 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
689 operator<( const iterator_range<IteratorT>& l, const ForwardRange& r )
691 return iterator_range_detail::less_than( l, r );
694 template< class Iterator1T, class Iterator2T >
696 operator<=( const iterator_range<Iterator1T>& l, const iterator_range<Iterator2T>& r )
698 return iterator_range_detail::less_or_equal_than( l, r );
701 template< class IteratorT, class ForwardRange >
702 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
703 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
706 operator<=( const iterator_range<IteratorT>& l, const ForwardRange& r )
708 return iterator_range_detail::less_or_equal_than( l, r );
711 template< class Iterator1T, class Iterator2T >
713 operator>( const iterator_range<Iterator1T>& l, const iterator_range<Iterator2T>& r )
715 return iterator_range_detail::greater_than( l, r );
718 template< class IteratorT, class ForwardRange >
719 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
720 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
723 operator>( const iterator_range<IteratorT>& l, const ForwardRange& r )
725 return iterator_range_detail::greater_than( l, r );
728 template< class Iterator1T, class Iterator2T >
730 operator>=( const iterator_range<Iterator1T>& l, const iterator_range<Iterator2T>& r )
732 return iterator_range_detail::greater_or_equal_than( l, r );
735 template< class IteratorT, class ForwardRange >
736 inline BOOST_DEDUCED_TYPENAME boost::enable_if<
737 mpl::not_<boost::is_base_and_derived<iterator_range_detail::iterator_range_tag, ForwardRange> >,
740 operator>=( const iterator_range<IteratorT>& l, const ForwardRange& r )
742 return iterator_range_detail::greater_or_equal_than( l, r );
745 #endif // BOOST_NO_FUNCTION_TEMPLATE_ORDERING
747 // iterator range utilities -----------------------------------------//
749 //! iterator_range construct helper
751 Construct an \c iterator_range from a pair of iterators
753 \param Begin A begin iterator
754 \param End An end iterator
755 \return iterator_range object
757 template< typename IteratorT >
758 inline iterator_range< IteratorT >
759 make_iterator_range( IteratorT Begin, IteratorT End )
761 return iterator_range<IteratorT>( Begin, End );
764 template<typename IteratorT, typename IntegerT>
765 inline iterator_range<IteratorT>
766 make_iterator_range_n(IteratorT first, IntegerT n)
768 return iterator_range<IteratorT>(first, boost::next(first, n));
771 #ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
773 template< typename Range >
774 inline iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<Range>::type >
775 make_iterator_range( Range& r )
777 return iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<Range>::type >
778 ( boost::begin( r ), boost::end( r ) );
782 //! iterator_range construct helper
784 Construct an \c iterator_range from a \c Range containing the begin
787 template< class ForwardRange >
788 inline iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<ForwardRange>::type >
789 make_iterator_range( ForwardRange& r )
791 return iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<ForwardRange>::type >
792 ( r, iterator_range_detail::range_tag() );
795 template< class ForwardRange >
796 inline iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<const ForwardRange>::type >
797 make_iterator_range( const ForwardRange& r )
799 return iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<const ForwardRange>::type >
800 ( r, iterator_range_detail::const_range_tag() );
803 #endif // BOOST_NO_FUNCTION_TEMPLATE_ORDERING
805 namespace iterator_range_detail
807 template< class Range >
808 inline iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<Range>::type >
809 make_range_impl( Range& r,
810 BOOST_DEDUCED_TYPENAME range_difference<Range>::type advance_begin,
811 BOOST_DEDUCED_TYPENAME range_difference<Range>::type advance_end )
814 // Not worth the effort
816 //if( advance_begin == 0 && advance_end == 0 )
817 // return make_iterator_range( r );
820 BOOST_DEDUCED_TYPENAME range_iterator<Range>::type
821 new_begin = boost::begin( r ),
822 new_end = boost::end( r );
823 std::advance( new_begin, advance_begin );
824 std::advance( new_end, advance_end );
825 return make_iterator_range( new_begin, new_end );
829 #ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
831 template< class Range >
832 inline iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<Range>::type >
833 make_iterator_range( Range& r,
834 BOOST_DEDUCED_TYPENAME range_difference<Range>::type advance_begin,
835 BOOST_DEDUCED_TYPENAME range_difference<Range>::type advance_end )
837 return iterator_range_detail::make_range_impl( r, advance_begin, advance_end );
842 template< class Range >
843 inline iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<Range>::type >
844 make_iterator_range( Range& r,
845 BOOST_DEDUCED_TYPENAME range_difference<Range>::type advance_begin,
846 BOOST_DEDUCED_TYPENAME range_difference<Range>::type advance_end )
848 return iterator_range_detail::make_range_impl( r, advance_begin, advance_end );
851 template< class Range >
852 inline iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<const Range>::type >
853 make_iterator_range( const Range& r,
854 BOOST_DEDUCED_TYPENAME range_difference<Range>::type advance_begin,
855 BOOST_DEDUCED_TYPENAME range_difference<Range>::type advance_end )
857 return iterator_range_detail::make_range_impl( r, advance_begin, advance_end );
860 #endif // BOOST_NO_FUNCTION_TEMPLATE_ORDERING
862 //! copy a range into a sequence
864 Construct a new sequence of the specified type from the elements
867 \param Range An input range
870 template< typename SeqT, typename Range >
871 inline SeqT copy_range( const Range& r )
873 return SeqT( boost::begin( r ), boost::end( r ) );
876 } // namespace 'boost'
878 #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1500))
879 #pragma warning( pop )