Fix out of bounds access within {front|back}_extended_deque with empty deque.

The insertion point is not correct with empty deque since the range
{next_down, next_up} is not half-open range.

include/boost/fusion/container/deque/deque.hpp

@@ -50,7 +50,7 @@ namespace boost { namespace fusion
         typedef bidirectional_traversal_tag category;
         typedef mpl::int_<0> size;
         typedef mpl::int_<0> next_up;
-        typedef mpl::int_<0> next_down;
+        typedef mpl::int_<-1> next_down;
         typedef mpl::false_ is_view;
 
         template <typename Sequence>
@@ -76,7 +76,7 @@ namespace boost { namespace fusion
         typedef typename detail::deque_keyed_values<Head, Tail...>::type base;
         typedef mpl::int_<(sizeof ...(Tail) + 1)> size;
         typedef mpl::int_<size::value> next_up;
-        typedef mpl::int_<((size::value == 0) ? 0 : -1)> next_down;
+        typedef mpl::int_<-1> next_down;
         typedef mpl::false_ is_view;
 
         BOOST_FUSION_GPU_ENABLED

include/boost/fusion/container/deque/detail/begin_impl.hpp

@@ -11,9 +11,6 @@
 #include <boost/fusion/support/config.hpp>
 #include <boost/fusion/container/deque/deque_iterator.hpp>
 
-#include <boost/mpl/equal_to.hpp>
-#include <boost/mpl/if.hpp>
-
 namespace boost { namespace fusion
 {
     struct deque_tag;
@@ -29,12 +26,8 @@ namespace boost { namespace fusion
             template<typename Sequence>
             struct apply
             {
-                typedef typename
+                typedef
-                    mpl::if_c<
+                    deque_iterator<Sequence, (Sequence::next_down::value + 1)>
-                        (Sequence::next_down::value == Sequence::next_up::value)
-                      , deque_iterator<Sequence, 0>
-                      , deque_iterator<Sequence, (Sequence::next_down::value + 1)>
-                    >::type
                 type;
 
                 BOOST_FUSION_GPU_ENABLED

include/boost/fusion/container/deque/detail/cpp03/deque.hpp

@@ -74,8 +74,7 @@ namespace boost { namespace fusion {
         typedef typename detail::deque_keyed_values<BOOST_PP_ENUM_PARAMS(FUSION_MAX_DEQUE_SIZE, T)>::type base;
         typedef typename detail::deque_initial_size<BOOST_PP_ENUM_PARAMS(FUSION_MAX_DEQUE_SIZE, T)>::type size;
         typedef mpl::int_<size::value> next_up;
-        typedef mpl::int_<
+        typedef mpl::int_<-1> next_down;
-            mpl::if_<mpl::equal_to<size, mpl::int_<0> >, mpl::int_<0>, mpl::int_<-1> >::type::value> next_down;
         typedef mpl::false_ is_view;
 
 #include <boost/fusion/container/deque/detail/cpp03/deque_forward_ctor.hpp>
@@ -167,7 +166,7 @@ FUSION_HASH endif
         typedef bidirectional_traversal_tag category;
         typedef mpl::int_<0> size;
         typedef mpl::int_<0> next_up;
-        typedef mpl::int_<0> next_down;
+        typedef mpl::int_<-1> next_down;
         typedef mpl::false_ is_view;
 
         template <typename Sequence>

include/boost/fusion/container/deque/detail/end_impl.hpp

@@ -11,9 +11,6 @@
 #include <boost/fusion/support/config.hpp>
 #include <boost/fusion/container/deque/deque_iterator.hpp>
 
-#include <boost/mpl/equal_to.hpp>
-#include <boost/mpl/if.hpp>
-
 namespace boost { namespace fusion
 {
     struct deque_tag;
@@ -29,12 +26,8 @@ namespace boost { namespace fusion
             template<typename Sequence>
             struct apply
             {
-                typedef typename
+                typedef
-                    mpl::if_c<
+                    deque_iterator<Sequence, Sequence::next_up::value>
-                        (Sequence::next_down::value == Sequence::next_up::value)
-                      , deque_iterator<Sequence, 0>
-                      , deque_iterator<Sequence, Sequence::next_up::value>
-                    >::type
                 type;
 
                 BOOST_FUSION_GPU_ENABLED

test/sequence/back_extended_deque.cpp

@@ -23,6 +23,45 @@
 int main()
 {
     using namespace boost::fusion;
+    {
+        typedef deque<> initial_deque_type;
+        initial_deque_type initial_deque;
+        typedef back_extended_deque<initial_deque_type, long> extended_type;
+        extended_type extended(initial_deque, 101L);
+
+        BOOST_TEST(size(extended) == 1);
+        BOOST_TEST(extended == make_vector(101L));
+        BOOST_TEST(*begin(extended) == 101L);
+        BOOST_TEST(*prior(end(extended)) == 101L);
+        BOOST_TEST(distance(begin(extended), end(extended)) == 1);
+    }
+    {
+        namespace mpl = boost::mpl;
+        typedef deque<> initial_deque_type;
+        typedef back_extended_deque<initial_deque_type, long> extended_type;
+
+        BOOST_MPL_ASSERT((boost::is_same<mpl::at_c<extended_type, 0>::type, long>));
+        BOOST_MPL_ASSERT((boost::is_same<mpl::deref<mpl::begin<extended_type>::type>::type, long>));
+        BOOST_MPL_ASSERT((mpl::equal_to<mpl::size<extended_type>::type, mpl::int_<1> >));
+    }
+    {
+        long l(101L);
+        typedef deque<> initial_deque_type;
+        initial_deque_type initial_deque;
+        typedef back_extended_deque<initial_deque_type, long&> extended_type;
+        extended_type extended(initial_deque, l);
+        BOOST_TEST(extended == make_vector(101L));
+
+        long l2(202L);
+        extended_type extended2(initial_deque_type(), l2);
+
+        extended = extended2;
+
+        BOOST_TEST(extended == make_vector(202L));
+
+        BOOST_TEST(l == l2);
+    }
+
     {
         typedef deque<int, char> initial_deque_type;
         initial_deque_type initial_deque(1, 'a');

test/sequence/front_extended_deque.cpp

@@ -23,6 +23,45 @@
 int main()
 {
     using namespace boost::fusion;
+    {
+        typedef deque<> initial_deque_type;
+        initial_deque_type initial_deque;
+        typedef front_extended_deque<initial_deque_type, int> extended_type;
+        extended_type extended(initial_deque, 1);
+
+        BOOST_TEST(size(extended) == 1);
+        BOOST_TEST(extended == make_vector(1));
+        BOOST_TEST(*begin(extended) == 1);
+        BOOST_TEST(*prior(end(extended)) == 1);
+        BOOST_TEST(distance(begin(extended), end(extended)) == 1);
+    }
+    {
+        namespace mpl = boost::mpl;
+        typedef deque<> initial_deque_type;
+        typedef front_extended_deque<initial_deque_type, int> extended_type;
+
+        BOOST_MPL_ASSERT((boost::is_same<mpl::at_c<extended_type, 0>::type, int>));
+        BOOST_MPL_ASSERT((boost::is_same<mpl::deref<mpl::begin<extended_type>::type>::type, int>));
+        BOOST_MPL_ASSERT((mpl::equal_to<mpl::size<extended_type>::type, mpl::int_<1> >));
+    }
+    {
+        int i(1);
+        typedef deque<> initial_deque_type;
+        initial_deque_type initial_deque;
+        typedef front_extended_deque<initial_deque_type, int&> extended_type;
+        extended_type extended(initial_deque, i);
+        BOOST_TEST(extended == make_vector(1));
+
+        int i2(2);
+        extended_type extended2(initial_deque_type(), i2);
+
+        extended = extended2;
+
+        BOOST_TEST(extended == make_vector(2));
+
+        BOOST_TEST(i == i2);
+    }
+
     {
         typedef deque<char, long> initial_deque_type;
         initial_deque_type initial_deque('a', 101L);