ticket 8028 - combine reimplemented and now documented.

doc/.gitignore

@@ -0,0 +1 @@
+*.html

doc/reference/utilities.qbk

@@ -273,6 +273,83 @@ sub_range<std::string>               sub = find_first( str, "ll" );
 
 [endsect]
 
+[section:combine Function combine]
+
+The `combine` function is used to make one range from multiple ranges. The
+`combine` function returns a `combined_range` which is an `iterator_range` of
+a `zip_iterator` from the Boost.Iterator library.
+
+[h4 Synopsis]
+
+``
+namespace boost
+{
+    namespace range
+    {
+
+template<typename IterTuple>
+class combined_range
+    : public iterator_range<zip_iterator<IterTuple> >
+{
+public:
+    combined_range(IterTuple first, IterTuple last);
+};
+
+template<typename... Ranges>
+auto combine(Ranges&&... rngs) ->
+    combined_range<decltype(boost::make_tuple(boost::begin(rngs)...))>
+
+    } // namespace range
+} // namespace boost
+``
+
+* [*Precondition:] For each type `r` in `Ranges`, `r` is a model of
+__single_pass_range__ or better.
+* [*Return Type:] `combined_range<tuple<typename range_iterator<Ranges>::type...> >`
+* [*Returned Range Category:] The minimum of the range category of every range
+`r` in `Ranges`.
+
+[h4 Example]
+
+``
+#include <boost/range/combine.hpp>
+#include <boost/foreach.hpp>
+#include <iostream>
+#include <vector>
+#include <list>
+
+int main(int, const char*[])
+{
+    std::vector<int> v;
+    std::list<char> l;
+    for (int i = 0; i < 5; ++i)
+    {
+        v.push_back(i);
+        l.push_back(static_cast<char>(i) + 'a');
+    }
+
+    int ti;
+    char tc;
+    BOOST_FOREACH(boost::tie(ti, tc), boost::combine(v, l))
+    {
+        std::cout << '(' << ti << ',' << tv << ')' << '\n';
+    }
+
+    return 0;
+}
+``
+
+This produces the output:
+``
+(0,a)
+(1,b)
+(2,c)
+(3,d)
+(4,e)
+``
+
+[endsect]
+
 [section:join Function join]
 
 The intention of the `join` function is to join two ranges into one longer range.

doc/upgrade.qbk

@@ -16,6 +16,8 @@ been noted that some calling code was relying on member functions such as
 due to `iterator_reference<Iter>::type` not being a reference. The suggested
 refactoring is to use `boost::size(rng)`.
 
+[endsect]
+
 [section:upgrade_from_1_49 Upgrade from version 1.49]
 
 # __size__ now returns the type Rng::size_type if the range has size_type;

include/boost/range/combine.hpp

@@ -9,296 +9,37 @@
 #ifndef BOOST_RANGE_COMBINE_HPP
 #define BOOST_RANGE_COMBINE_HPP
 
-#include <boost/iterator/zip_iterator.hpp>
-#include <boost/tuple/tuple.hpp>
-#include <boost/range/iterator.hpp>
-#include <boost/range/iterator_range.hpp>
-#include <boost/type_traits/is_void.hpp>
-#include <boost/type_traits/is_same.hpp>
-#include <boost/mpl/eval_if.hpp>
-#include <boost/mpl/int.hpp>
-#include <boost/mpl/plus.hpp>
-#include <boost/mpl/arithmetic.hpp>
 #include <boost/config.hpp>
+#include <boost/range/iterator_range_core.hpp>
+#include <boost/iterator/zip_iterator.hpp>
 
 namespace boost
 {
-    namespace range_detail
+    namespace range
     {
-        struct void_ { typedef void_ type; };
-    }
 
-    template<> struct range_iterator< ::boost::range_detail::void_ >
+template<typename IterTuple>
+class combined_range
+        : public iterator_range<zip_iterator<IterTuple> >
 {
-       typedef ::boost::tuples::null_type type;
+    typedef iterator_range<zip_iterator<IterTuple> > base;
-    };
-
-    namespace range_detail
-    {
-        inline ::boost::tuples::null_type range_begin( ::boost::range_detail::void_& )
-        { return ::boost::tuples::null_type(); }
-
-        inline ::boost::tuples::null_type range_begin( const ::boost::range_detail::void_& )
-        { return ::boost::tuples::null_type(); }
-
-        inline ::boost::tuples::null_type range_end( ::boost::range_detail::void_& )
-        { return ::boost::tuples::null_type(); }
-
-        inline ::boost::tuples::null_type range_end( const ::boost::range_detail::void_& )
-        { return ::boost::tuples::null_type(); }
-
-        template< class T >
-        struct tuple_iter
-        {
-            typedef BOOST_DEDUCED_TYPENAME ::boost::mpl::eval_if_c<
-                ::boost::is_same<T, ::boost::range_detail::void_ >::value,
-                ::boost::mpl::identity< ::boost::tuples::null_type >,
-                ::boost::range_iterator<T>
-            >::type type;
-        };
-
-        template< class Rng1, class Rng2 >
-        struct tuple_range
-        {
-            typedef BOOST_DEDUCED_TYPENAME ::boost::mpl::eval_if_c<
-                ::boost::is_same<Rng1, ::boost::range_detail::void_ >::value,
-                ::boost::range_detail::void_,
-                ::boost::mpl::identity<Rng1>
-            >::type type;
-        };
-
-        template
-        <
-            class R1,
-            class R2,
-            class R3,
-            class R4,
-            class R5,
-            class R6
-        >
-        struct generate_tuple
-        {
-            typedef ::boost::tuples::tuple<
-                        BOOST_DEDUCED_TYPENAME tuple_iter<R1>::type,
-                        BOOST_DEDUCED_TYPENAME tuple_iter<R2>::type,
-                        BOOST_DEDUCED_TYPENAME tuple_iter<R3>::type,
-                        BOOST_DEDUCED_TYPENAME tuple_iter<R4>::type,
-                        BOOST_DEDUCED_TYPENAME tuple_iter<R5>::type,
-                        BOOST_DEDUCED_TYPENAME tuple_iter<R6>::type
-                    > type;
-
-            static type begin( R1& r1, R2& r2, R3& r3, R4& r4, R5& r5, R6& r6 )
-            {
-                return ::boost::tuples::make_tuple( ::boost::begin(r1),
-                                                    ::boost::begin(r2),
-                                                    ::boost::begin(r3),
-                                                    ::boost::begin(r4),
-                                                    ::boost::begin(r5),
-                                                    ::boost::begin(r6) );
-            }
-
-            static type end( R1& r1, R2& r2, R3& r3, R4& r4, R5& r5, R6& r6 )
-            {
-                return ::boost::tuples::make_tuple( ::boost::end(r1),
-                                                    ::boost::end(r2),
-                                                    ::boost::end(r3),
-                                                    ::boost::end(r4),
-                                                    ::boost::end(r5),
-                                                    ::boost::end(r6) );
-            }
-        };
-
-        template
-        <
-            class R1,
-            class R2 = void_,
-            class R3 = void_,
-            class R4 = void_,
-            class R5 = void_,
-            class R6 = void_
-        >
-        struct zip_rng
-            : iterator_range<
-                zip_iterator<
-                    BOOST_DEDUCED_TYPENAME generate_tuple<R1,R2,R3,R4,R5,R6>::type
-                >
-            >
-        {
-        private:
-            typedef generate_tuple<R1,R2,R3,R4,R5,R6>        generator_t;
-            typedef BOOST_DEDUCED_TYPENAME generator_t::type tuple_t;
-            typedef zip_iterator<tuple_t>                    zip_iter_t;
-            typedef iterator_range<zip_iter_t>               base_t;
-
 public:
-            zip_rng( R1& r1, R2& r2, R3& r3, R4& r4, R5& r5, R6& r6 )
+    combined_range(IterTuple first, IterTuple last)
-            : base_t( zip_iter_t( generator_t::begin(r1,r2,r3,r4,r5,r6) ),
+        : base(first, last)
-                      zip_iter_t( generator_t::end(r1,r2,r3,r4,r5,r6) ) )
     {
-                BOOST_ASSERT(::boost::distance(r1) <= ::boost::distance(r2));
-                BOOST_ASSERT(::boost::distance(r1) <= ::boost::distance(r3));
-                BOOST_ASSERT(::boost::distance(r1) <= ::boost::distance(r4));
-                BOOST_ASSERT(::boost::distance(r1) <= ::boost::distance(r5));
-                BOOST_ASSERT(::boost::distance(r1) <= ::boost::distance(r6));
-            }
-
-            template< class Zip, class Rng >
-            zip_rng( Zip& z, Rng& r )
-            : base_t( zip_iter_t( generator_t::begin( z, r ) ),
-                      zip_iter_t( generator_t::end( z, r ) ) )
-            {
-
-                // @todo: tuple::begin( should be overloaded for this situation
-            }
-
-            struct tuple_length : ::boost::tuples::length<tuple_t>
-            { };
-
-            template< unsigned N >
-            struct get
-            {
-                template< class Z, class R >
-                static BOOST_DEDUCED_TYPENAME ::boost::tuples::element<N,tuple_t>::type begin( Z& z, R& )
-                {
-                    return get<N>( z.begin().get_iterator_tuple() );
-                }
-
-                template< class Z, class R >
-                static BOOST_DEDUCED_TYPENAME ::boost::tuples::element<N,tuple_t>::type end( Z& z, R& r )
-                {
-                    return get<N>( z.end().get_iterator_tuple() );
     }
 };
 
-        };
+    } // namespace range
-
-        template< class Rng1, class Rng2 >
-        struct zip_range
-            : iterator_range<
-                zip_iterator<
-                    ::boost::tuples::tuple<
-                        BOOST_DEDUCED_TYPENAME ::boost::range_iterator<Rng1>::type,
-                        BOOST_DEDUCED_TYPENAME ::boost::range_iterator<Rng2>::type
-                    >
-                >
-            >
-        {
-        private:
-            typedef zip_iterator<
-                        ::boost::tuples::tuple<
-                            BOOST_DEDUCED_TYPENAME ::boost::range_iterator<Rng1>::type,
-                            BOOST_DEDUCED_TYPENAME ::boost::range_iterator<Rng2>::type
-                        >
-                    > zip_iter_t;
-            typedef iterator_range<zip_iter_t> base_t;
-
-        public:
-            zip_range( Rng1& r1, Rng2& r2 )
-            : base_t( zip_iter_t( ::boost::tuples::make_tuple(::boost::begin(r1),
-                                                              ::boost::begin(r2)) ),
-                      zip_iter_t( ::boost::tuples::make_tuple(::boost::end(r1),
-                                                              ::boost::end(r2)) ) )
-            {
-                BOOST_ASSERT(::boost::distance(r1) <= ::boost::distance(r2));
-            }
-        };
-
-        template< class Rng1, class Rng2, class Rng3 >
-        struct zip_range3
-            : iterator_range<
-                zip_iterator<
-                    ::boost::tuples::tuple<
-                        BOOST_DEDUCED_TYPENAME ::boost::range_iterator<Rng1>::type,
-                        BOOST_DEDUCED_TYPENAME ::boost::range_iterator<Rng2>::type,
-                        BOOST_DEDUCED_TYPENAME ::boost::range_iterator<Rng3>::type
-                    >
-                >
-            >
-        {
-        private:
-            typedef zip_iterator<
-                ::boost::tuples::tuple<
-                    BOOST_DEDUCED_TYPENAME ::boost::range_iterator<Rng1>::type,
-                    BOOST_DEDUCED_TYPENAME ::boost::range_iterator<Rng2>::type,
-                    BOOST_DEDUCED_TYPENAME ::boost::range_iterator<Rng3>::type
-                >
-            > zip_iter_t;
-            typedef iterator_range<zip_iter_t> base_t;
-
-        public:
-            zip_range3( Rng1& r1, Rng2& r2, Rng3& r3 )
-            : base_t( zip_iter_t( ::boost::tuples::make_tuple(::boost::begin(r1),
-                                                              ::boost::begin(r2),
-                                                              ::boost::begin(r3)) ),
-                      zip_iter_t( ::boost::tuples::make_tuple(::boost::end(r1),
-                                                              ::boost::end(r2),
-                                                              ::boost::end(r3)) )
-                    )
-            {
-                BOOST_ASSERT(::boost::distance(r1) <= ::boost::distance(r2));
-                BOOST_ASSERT(::boost::distance(r1) <= ::boost::distance(r3));
-            }
-        };
-
-
-        struct combine_tag {};
-
-        template< class Rng >
-        inline zip_rng<Rng>
-        operator&( combine_tag, Rng& r )
-        {
-            return zip_rng<Rng>(r);
-        }
-
-        template< class Rng >
-        inline iterator_range<const Rng>
-        operator&( combine_tag, const Rng& r )
-        {
-            return iterator_range<const Rng>(r);
-        }
-
-        template
-        <
-            class R1,
-            class R2,
-            class R3,
-            class R4,
-            class R5,
-            class Rng
-        >
-        inline BOOST_DEDUCED_TYPENAME zip_rng<R1,R2,R3,R4,R5>::next
-        operator&( const zip_rng<R1,R2,R3,R4,R5>& zip,
-                   Rng& r )
-        {
-            return zip_rng<R1,R2,R3,R4,R5>::next( zip, r );
-        }
-
-    } // namespace range_detail
-
-    template< class Rng1, class Rng2 >
-    inline ::boost::range_detail::zip_range<Rng1, Rng2> combine( Rng1& r1, Rng2& r2 )
-    {
-        return ::boost::range_detail::zip_range<Rng1, Rng2>(r1, r2);
-    }
-
-    template< class Rng1, class Rng2 >
-    inline ::boost::range_detail::zip_range<const Rng1, Rng2> combine( const Rng1& r1, Rng2& r2 )
-    {
-        return ::boost::range_detail::zip_range<const Rng1, Rng2>(r1, r2);
-    }
-
-    template< class Rng1, class Rng2 >
-    inline ::boost::range_detail::zip_range<Rng1, const Rng2> combine( Rng1& r1, const Rng2& r2 )
-    {
-        return ::boost::range_detail::zip_range<Rng1, const Rng2>(r1, r2);
-    }
-
-    template< class Rng1, class Rng2 >
-    inline ::boost::range_detail::zip_range<const Rng1, const Rng2> combine( const Rng1& r1, const Rng2& r2 )
-    {
-        return ::boost::range_detail::zip_range<const Rng1, const Rng2>(r1, r2);
-    }
-
 } // namespace boost
 
+#if defined(BOOST_NO_CXX11_AUTO_DECLARATIONS) || \
+    defined(BOOST_NO_CXX11_DECLTYPE) || \
+    defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) || \
+    defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
+#   include <boost/range/detail/combine_cxx03.hpp>
+#else
+#   include <boost/range/detail/combine_cxx11.hpp>
+#endif
+
 #endif

include/boost/range/const_iterator.hpp

@@ -20,6 +20,7 @@
 
 #include <boost/range/detail/extract_optional_type.hpp>
 #include <boost/type_traits/remove_const.hpp>
+#include <boost/type_traits/remove_reference.hpp>
 #include <cstddef>
 #include <utility>
 
@@ -29,12 +30,14 @@ namespace boost
     // default
     //////////////////////////////////////////////////////////////////////////
     
-    namespace range_detail {
+    namespace range_detail
+    {
+
 BOOST_RANGE_EXTRACT_OPTIONAL_TYPE( const_iterator )
-    }
 
 template< typename C >
-    struct range_const_iterator : range_detail::extract_const_iterator<C>
+struct range_const_iterator
+        : extract_const_iterator<C>
 {};
 
 //////////////////////////////////////////////////////////////////////////
@@ -57,6 +60,16 @@ namespace boost
     typedef const T* type;
 };
 
+    } // namespace range_detail
+
+template<typename C>
+struct range_const_iterator
+        : range_detail::range_const_iterator<
+            typename remove_reference<C>::type
+        >
+{
+};
+
 } // namespace boost
 
 

include/boost/range/const_reverse_iterator.hpp

@@ -16,6 +16,7 @@
 #endif
 
 #include <boost/range/reverse_iterator.hpp>
+#include <boost/type_traits/remove_reference.hpp>
 
 namespace boost
 {
@@ -24,7 +25,8 @@ namespace boost
     //
     
     template< typename C >
-    struct range_const_reverse_iterator : range_reverse_iterator<const C>
+    struct range_const_reverse_iterator
+            : range_reverse_iterator<const typename remove_reference<C>::type>
     { };
     
 } // namespace boost

include/boost/range/detail/combine_cxx03.hpp

@@ -0,0 +1,131 @@
+// Boost.Range library
+//
+//  Copyright Neil Groves 2014. 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_COMBINE_CXX03_HPP
+#define BOOST_RANGE_DETAIL_COMBINE_CXX03_HPP
+
+#ifndef BOOST_RANGE_MIN_COMBINE_ARGS
+#define BOOST_RANGE_MIN_COMBINE_ARGS 2
+#endif
+
+#ifndef BOOST_RANGE_MAX_COMBINE_ARGS
+#define BOOST_RANGE_MAX_COMBINE_ARGS 5
+#endif
+
+#include <boost/config.hpp>
+#include <boost/iterator/zip_iterator.hpp>
+#include <boost/preprocessor/arithmetic/dec.hpp>
+#include <boost/preprocessor/arithmetic/div.hpp>
+#include <boost/preprocessor/arithmetic/mul.hpp>
+#include <boost/preprocessor/control.hpp>
+#include <boost/preprocessor/control/while.hpp>
+#include <boost/preprocessor/facilities/empty.hpp>
+#include <boost/preprocessor/facilities/identity.hpp>
+#include <boost/preprocessor/iteration/local.hpp>
+#include <boost/preprocessor/punctuation/comma.hpp>
+#include <boost/preprocessor/repetition.hpp>
+#include <boost/preprocessor/tuple/elem.hpp>
+#include <boost/range/iterator_range_core.hpp>
+#include <boost/type_traits/remove_reference.hpp>
+#include <boost/mpl/transform.hpp>
+#include <boost/utility/result_of.hpp>
+
+#include <vector>
+#include <list>
+
+namespace boost
+{
+    namespace range_detail
+    {
+
+template<typename F, typename T, int SIZE>
+struct combined_result_impl;
+
+template<typename F, typename T>
+struct combined_result
+    : combined_result_impl<F, T, tuples::length<T>::value>
+{
+};
+
+#define BOOST_RANGE_combined_element(z, n, data) \
+    typename tuples::element<n, T>::type
+
+#define BOOST_RANGE_combined_result(z, n, data) \
+    template<typename F, typename T> \
+    struct combined_result_impl <F,T,n> \
+        : result_of<F(BOOST_PP_ENUM(n, BOOST_RANGE_combined_element, ~))> \
+    { \
+    };
+
+#define BOOST_PP_LOCAL_MACRO(n) BOOST_RANGE_combined_result(~,n,~)
+
+#define BOOST_PP_LOCAL_LIMITS (BOOST_RANGE_MIN_COMBINE_ARGS, \
+                               BOOST_RANGE_MAX_COMBINE_ARGS)
+#include BOOST_PP_LOCAL_ITERATE()
+
+#define BOOST_RANGE_combined_get(z, n, data) get<n>(tuple)
+
+#define BOOST_RANGE_combined_unpack(z, n, data) \
+    template<typename F, typename T> inline \
+    typename combined_result<F,T>::type \
+    unpack_(mpl::int_<n>, F f, const T& tuple) \
+    { \
+        return f(BOOST_PP_ENUM(n, BOOST_RANGE_combined_get, ~)); \
+    }
+
+#define BOOST_PP_LOCAL_MACRO(n) BOOST_RANGE_combined_unpack(~,n,~)
+#define BOOST_PP_LOCAL_LIMITS (BOOST_RANGE_MIN_COMBINE_ARGS, \
+                               BOOST_RANGE_MAX_COMBINE_ARGS)
+#include BOOST_PP_LOCAL_ITERATE()
+
+} // namespace range_detail
+
+namespace range
+{
+
+#define BOOST_RANGE_combined_seq(z, n, data) boost::data(BOOST_PP_CAT(r,n))
+
+#ifdef BOOST_NO_RVALUE_REFERENCES
+
+#include <boost/range/detail/combine_no_rvalue.hpp>
+
+#else // by using rvalue references we avoid requiring 2^n overloads.
+
+#include <boost/range/detail/combine_rvalue.hpp>
+
+#endif
+
+#define BOOST_PP_LOCAL_MACRO(n) BOOST_RANGE_combine(~,n,~)
+#define BOOST_PP_LOCAL_LIMITS (BOOST_RANGE_MIN_COMBINE_ARGS, \
+                               BOOST_RANGE_MAX_COMBINE_ARGS)
+#include BOOST_PP_LOCAL_ITERATE()
+
+    } // namespace range
+
+    using boost::range::combine;
+
+} // namespace boost
+
+#endif // include guard
+
+#undef BOOST_RANGE_combined_element
+#undef BOOST_RANGE_combined_result
+#undef BOOST_RANGE_combined_get
+#undef BOOST_RANGE_combined_unpack
+#undef BOOST_RANGE_combined_seq
+#undef BOOST_RANGE_combined_exp_pred
+#undef BOOST_RANGE_combined_exp_op
+#undef BOOST_RANGE_combined_exp
+#undef BOOST_RANGE_combined_bitset_pred
+#undef BOOST_RANGE_combined_bitset_op
+#undef BOOST_RANGE_combined_bitset
+#undef BOOST_RANGE_combined_range_iterator
+#undef BOOST_RANGE_combined_args
+#undef BOOST_RANGE_combine_impl
+#undef BOOST_RANGE_combine

include/boost/range/detail/combine_cxx11.hpp

@@ -0,0 +1,40 @@
+//  Copyright Neil Groves 2014. 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_COMBINE_CXX11_HPP
+#define BOOST_RANGE_DETAIL_COMBINE_CXX11_HPP
+
+#include <boost/range/iterator_range_core.hpp>
+#include <boost/range/iterator.hpp>
+#include <boost/range/begin.hpp>
+#include <boost/range/end.hpp>
+#include <boost/iterator/zip_iterator.hpp>
+
+#include <fstream>
+
+namespace boost
+{
+    namespace range
+    {
+
+template<typename... Ranges>
+auto combine(Ranges&&... rngs) ->
+    combined_range<decltype(boost::make_tuple(boost::begin(rngs)...))>
+{
+    return combined_range<decltype(boost::make_tuple(boost::begin(rngs)...))>(
+                boost::make_tuple(boost::begin(rngs)...),
+                boost::make_tuple(boost::end(rngs)...));
+}
+
+    } // namespace range
+
+using range::combine;
+
+} // namespace boost
+
+#endif // include guard

include/boost/range/detail/combine_no_rvalue.hpp

@@ -0,0 +1,73 @@
+// Boost.Range library
+//
+//  Copyright Neil Groves 2014. 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/
+//
+#define BOOST_RANGE_combined_exp_pred(d, data) BOOST_PP_TUPLE_ELEM(3, 0, data)
+
+#define BOOST_RANGE_combined_exp_op(d, data) \
+ ( \
+    BOOST_PP_DEC( \
+       BOOST_PP_TUPLE_ELEM(3, 0, data) \
+    ), \
+    BOOST_PP_TUPLE_ELEM(3, 1, data), \
+    BOOST_PP_MUL_D( \
+       d, \
+       BOOST_PP_TUPLE_ELEM(3, 2, data), \
+       BOOST_PP_TUPLE_ELEM(3, 1, data) \
+    ) \
+ )
+
+#define BOOST_RANGE_combined_exp(x, n) \
+  BOOST_PP_TUPLE_ELEM(3, 2, \
+  BOOST_PP_WHILE(BOOST_RANGE_combined_exp_pred, \
+                 BOOST_RANGE_combined_exp_op, (n, x, 1)))
+
+#define BOOST_RANGE_combined_bitset_pred(n, state) \
+    BOOST_PP_TUPLE_ELEM(2,1,state)
+
+#define BOOST_RANGE_combined_bitset_op(d, state) \
+    (BOOST_PP_DIV_D(d, BOOST_PP_TUPLE_ELEM(2,0,state), 2), \
+     BOOST_PP_DEC(BOOST_PP_TUPLE_ELEM(2,1,state)))
+
+#define BOOST_RANGE_combined_bitset(i, n) \
+BOOST_PP_MOD(BOOST_PP_TUPLE_ELEM(2, 0, \
+      BOOST_PP_WHILE(BOOST_RANGE_combined_bitset_pred, \
+                     BOOST_RANGE_combined_bitset_op, (i,n))), 2)
+
+#define BOOST_RANGE_combined_range_iterator(z, n, i) \
+  typename range_iterator< \
+      BOOST_PP_CAT(R,n)          \
+      BOOST_PP_IF( \
+          BOOST_RANGE_combined_bitset(i,n), \
+          BOOST_PP_IDENTITY(const), \
+          BOOST_PP_EMPTY)() \
+  >::type
+
+#define BOOST_RANGE_combined_args(z, n, i) \
+  BOOST_PP_CAT(R, n) \
+  BOOST_PP_IF(BOOST_RANGE_combined_bitset(i,n), const&, &)  \
+  BOOST_PP_CAT(r, n)
+
+#define BOOST_RANGE_combine_impl(z, i, n)\
+    template<BOOST_PP_ENUM_PARAMS(n, typename R)> \
+    inline range::combined_range< \
+        boost::tuple<BOOST_PP_ENUM(n, BOOST_RANGE_combined_range_iterator, i)> \
+    > \
+    combine(BOOST_PP_ENUM(n, BOOST_RANGE_combined_args, i)) \
+    { \
+        typedef tuple< \
+            BOOST_PP_ENUM(n, BOOST_RANGE_combined_range_iterator, i) \
+        > rng_tuple_t;   \
+        return range::combined_range<rng_tuple_t>( \
+            rng_tuple_t(BOOST_PP_ENUM(n, BOOST_RANGE_combined_seq, begin)), \
+            rng_tuple_t(BOOST_PP_ENUM(n, BOOST_RANGE_combined_seq, end))); \
+    }
+
+
+#define BOOST_RANGE_combine(z, n, data) \
+  BOOST_PP_REPEAT(BOOST_RANGE_combined_exp(2,n), BOOST_RANGE_combine_impl, n)

include/boost/range/detail/combine_rvalue.hpp

@@ -0,0 +1,32 @@
+// Boost.Range library
+//
+//  Copyright Neil Groves 2014. 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/
+//
+#define BOOST_RANGE_combined_args(z, n, i) \
+    BOOST_PP_CAT(R, n)&& BOOST_PP_CAT(r, n)
+
+#define BOOST_RANGE_combined_range_iterator(z, n, i) \
+    typename range_iterator< \
+        typename remove_reference<BOOST_PP_CAT(R,n)>::type \
+  >::type
+
+
+#define BOOST_RANGE_combine(z, n, data) \
+    template <BOOST_PP_ENUM_PARAMS(n, typename R)> \
+    inline range::combined_range< \
+        tuple<BOOST_PP_ENUM(n, BOOST_RANGE_combined_range_iterator, ~)> \
+    > \
+    combine(BOOST_PP_ENUM(n, BOOST_RANGE_combined_args, ~)) \
+    { \
+        typedef tuple< \
+            BOOST_PP_ENUM(n, BOOST_RANGE_combined_range_iterator, ~) \
+        > rng_tuple_t; \
+        return range::combined_range<rng_tuple_t>( \
+            rng_tuple_t(BOOST_PP_ENUM(n, BOOST_RANGE_combined_seq, begin)), \
+            rng_tuple_t(BOOST_PP_ENUM(n, BOOST_RANGE_combined_seq, end))); \
+    }

include/boost/range/iterator.hpp

@@ -57,10 +57,15 @@ namespace boost
            
 #else  
 
-        typedef BOOST_RANGE_DEDUCED_TYPENAME 
+    private:
-            mpl::eval_if_c< is_const<C>::value, 
+        typedef typename remove_reference<C>::type param_t;
-                            range_const_iterator< typename remove_const<C>::type >,
+
-                            range_mutable_iterator<C> >::type type;
+    public:
+        typedef typename mpl::eval_if_c<
+            is_const<param_t>::value,
+            range_const_iterator<typename remove_const<param_t>::type>,
+            range_mutable_iterator<param_t>
+        >::type type;
         
 #endif         
     };

test/combine.cpp

@@ -1,5 +1,7 @@
 // Boost.Range library
 //
+// Copyright Neil Groves 2014
+//
 //  Copyright Thorsten Ottosen 2006. Use, modification and
 //  distribution is subject to the Boost Software License, Version
 //  1.0. (See accompanying file LICENSE_1_0.txt or copy at
@@ -7,65 +9,152 @@
 //
 // For more information, see http://www.boost.org/libs/range/
 //
-
 #include <boost/range/combine.hpp>
+
+#include <boost/range/algorithm_ext/push_back.hpp>
+
 #include <boost/test/test_tools.hpp>
 #include <boost/test/unit_test.hpp>
-#include <boost/tuple/tuple.hpp>
 #include <boost/foreach.hpp>
 #include <vector>
 
-
+namespace boost_range_test
-struct add
 {
-    template< class T >
+    namespace
-    int operator()( const T& tuple ) const
     {
-        return boost::get<0>(tuple) + boost::get<1>(tuple);
-    }
-};
 
-template< class CombinedRng >
+template<typename ContRef1, typename ContRef2>
-void apply( const CombinedRng& r )
+void test_combine2()
 {
     std::vector<int> v;
-    typedef BOOST_DEDUCED_TYPENAME boost::range_iterator<const CombinedRng>::type iterator_t;
+    std::list<int> l;
 
-    iterator_t e = boost::end(r);
+    for (int i = 0; i < 10; ++i)
-    for (iterator_t i = boost::begin(r); i != e; ++i)
     {
+        v.push_back(i);
+        l.push_back(i * 2);
+    }
+
+    ContRef1& in1 = v;
+    ContRef2& in2 = l;
+
+    std::vector<boost::tuple<int,int> > output;
+    boost::push_back(output, boost::combine(in1, in2));
+
+    int index = 0;
+    int i1, i2;
+    BOOST_FOREACH(boost::tie(i1,i2), output)
+    {
+        BOOST_CHECK_EQUAL(i1, index);
+        BOOST_CHECK_EQUAL(i2, index * 2);
+        ++index;
     }
 }
 
-void test_combine()
+template<typename ContRef1, typename ContRef2, typename ContRef3>
+void test_combine3()
 {
-    std::vector<int> v1, v2, v3;
+    std::vector<int> v1;
-    for (int i = 1; i <= 4; ++i)
+    std::vector<int> v2;
+    std::vector<int> v3;
+
+    for (int i = 0; i < 10; ++i)
     {
         v1.push_back(i);
-        v2.push_back(i);
+        v2.push_back(i * 2);
+        v3.push_back(i * 3);
     }
 
-    int i1, i2;
+    ContRef1& in1 = v1;
-    BOOST_FOREACH( boost::tie( i1, i2 ), boost::combine(v1,v2) )
+    ContRef2& in2 = v2;
+    ContRef3& in3 = v3;
+
+    std::vector<boost::tuple<int,int,int> > output;
+    boost::push_back(output, boost::combine(in1, in2, in3));
+
+    int index = 0;
+    int i1, i2, i3;
+
+    BOOST_FOREACH(boost::tie(i1,i2,i3), output)
     {
-        v3.push_back( i1 + i2 );
+        BOOST_CHECK_EQUAL(i1, index);
+        BOOST_CHECK_EQUAL(i2, index * 2);
+        BOOST_CHECK_EQUAL(i3, index * 3);
+        ++index;
+    }
 }
 
-    BOOST_CHECK_EQUAL( v3.size(), v1.size() );
+    } // anonymous namespace
-}
+} // namespace boost_range_test
 
-
+boost::unit_test::test_suite* init_unit_test_suite(int, char*[] )
-
-using boost::unit_test::test_suite;
-
-test_suite* init_unit_test_suite( int argc, char* argv[] )
 {
-    test_suite* test = BOOST_TEST_SUITE( "Range Test Suite" );
+    boost::unit_test::test_suite* test =
+            BOOST_TEST_SUITE( "Boost.Range combine() test suite" );
 
-    test->add( BOOST_TEST_CASE( &test_combine ) );
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine2<
+                        const std::vector<int>, const std::list<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine2<
+                        const std::vector<int>, std::list<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine2<
+                        std::vector<int>, const std::list<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine2<
+                        std::vector<int>, std::list<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine3<
+                        std::vector<int>,
+                        std::vector<int>,
+                        std::vector<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine3<
+                        std::vector<int>,
+                        std::vector<int>,
+                        const std::vector<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine3<
+                        std::vector<int>,
+                        const std::vector<int>,
+                        std::vector<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine3<
+                        std::vector<int>,
+                        const std::vector<int>,
+                        const std::vector<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine3<
+                        const std::vector<int>,
+                        std::vector<int>,
+                        std::vector<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine3<
+                        const std::vector<int>,
+                        std::vector<int>,
+                        const std::vector<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine3<
+                        const std::vector<int>,
+                        const std::vector<int>,
+                        std::vector<int> >)));
+
+    test->add(BOOST_TEST_CASE((
+            &boost_range_test::test_combine3<
+                        const std::vector<int>,
+                        const std::vector<int>,
+                        const std::vector<int> >)));
 
     return test;
 }
-
-