diff -r 000000000000 -r bde4ae8d615e os/ossrv/ossrv_pub/boost_apis/boost/numeric/ublas/symmetric.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/os/ossrv/ossrv_pub/boost_apis/boost/numeric/ublas/symmetric.hpp	Fri Jun 15 03:10:57 2012 +0200
@@ -0,0 +1,2133 @@
+//
+//  Copyright (c) 2000-2002
+//  Joerg Walter, Mathias Koch
+//
+//  Permission to use, copy, modify, distribute and sell this software
+//  and its documentation for any purpose is hereby granted without fee,
+//  provided that the above copyright notice appear in all copies and
+//  that both that copyright notice and this permission notice appear
+//  in supporting documentation.  The authors make no representations
+//  about the suitability of this software for any purpose.
+//  It is provided "as is" without express or implied warranty.
+//
+//  The authors gratefully acknowledge the support of
+//  GeNeSys mbH & Co. KG in producing this work.
+//
+
+#ifndef _BOOST_UBLAS_SYMMETRIC_
+#define _BOOST_UBLAS_SYMMETRIC_
+
+#include <boost/numeric/ublas/matrix.hpp>
+#include <boost/numeric/ublas/detail/temporary.hpp>
+
+// Iterators based on ideas of Jeremy Siek
+// Symmetric matrices are square. Thanks to Peter Schmitteckert for spotting this.
+
+namespace boost { namespace numeric { namespace ublas {
+
+    template<class M>
+    bool is_symmetric (const M &m) {
+        typedef typename M::size_type size_type;
+
+        if (m.size1 () != m.size2 ())
+            return false;
+        size_type size = BOOST_UBLAS_SAME (m.size1 (), m.size2 ());
+        for (size_type i = 0; i < size; ++ i) {
+            for (size_type j = i; j < size; ++ j) {
+                if (m (i, j) != m (j, i))
+                    return false;
+            }
+        }
+        return true;
+    }
+
+    // Array based symmetric matrix class
+    template<class T, class TRI, class L, class A>
+    class symmetric_matrix:
+        public matrix_container<symmetric_matrix<T, TRI, L, A> > {
+
+        typedef T *pointer;
+        typedef TRI triangular_type;
+        typedef L layout_type;
+        typedef symmetric_matrix<T, TRI, L, A> self_type;
+    public:
+#ifdef BOOST_UBLAS_ENABLE_PROXY_SHORTCUTS
+        using matrix_container<self_type>::operator ();
+#endif
+        typedef typename A::size_type size_type;
+        typedef typename A::difference_type difference_type;
+        typedef T value_type;
+        typedef const T &const_reference;
+        typedef T &reference;
+        typedef A array_type;
+
+        typedef const matrix_reference<const self_type> const_closure_type;
+        typedef matrix_reference<self_type> closure_type;
+        typedef vector<T, A> vector_temporary_type;
+        typedef matrix<T, L, A> matrix_temporary_type;  // general sub-matrix
+        typedef packed_tag storage_category;
+        typedef typename L::orientation_category orientation_category;
+
+        // Construction and destruction
+        BOOST_UBLAS_INLINE
+        symmetric_matrix ():
+            matrix_container<self_type> (),
+            size_ (0), data_ (0) {}
+        BOOST_UBLAS_INLINE
+        symmetric_matrix (size_type size):
+            matrix_container<self_type> (),
+            size_ (BOOST_UBLAS_SAME (size, size)), data_ (triangular_type::packed_size (layout_type (), size, size)) {
+        }
+        BOOST_UBLAS_INLINE
+        symmetric_matrix (size_type size1, size_type size2):
+            matrix_container<self_type> (),
+            size_ (BOOST_UBLAS_SAME (size1, size2)), data_ (triangular_type::packed_size (layout_type (), size1, size2)) {
+        }
+        BOOST_UBLAS_INLINE
+        symmetric_matrix (size_type size, const array_type &data):
+            matrix_container<self_type> (),
+            size_ (size), data_ (data) {}
+        BOOST_UBLAS_INLINE
+        symmetric_matrix (const symmetric_matrix &m):
+            matrix_container<self_type> (),
+            size_ (m.size_), data_ (m.data_) {}
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_matrix (const matrix_expression<AE> &ae):
+            matrix_container<self_type> (),
+            size_ (BOOST_UBLAS_SAME (ae ().size1 (), ae ().size2 ())),
+            data_ (triangular_type::packed_size (layout_type (), size_, size_)) {
+            matrix_assign<scalar_assign> (*this, ae);
+        }
+
+        // Accessors
+        BOOST_UBLAS_INLINE
+        size_type size1 () const {
+            return size_;
+        }
+        BOOST_UBLAS_INLINE
+        size_type size2 () const {
+            return size_;
+        }
+
+        // Storage accessors
+        BOOST_UBLAS_INLINE
+        const array_type &data () const {
+            return data_;
+        }
+        BOOST_UBLAS_INLINE
+        array_type &data () {
+            return data_;
+        }
+
+        // Resizing
+        BOOST_UBLAS_INLINE
+        void resize (size_type size, bool preserve = true) {
+            if (preserve) {
+                self_type temporary (size, size);
+                detail::matrix_resize_preserve<layout_type> (*this, temporary);
+            }
+            else {
+                data ().resize (triangular_type::packed_size (layout_type (), size, size));
+                size_ = size;
+            }
+        }
+        BOOST_UBLAS_INLINE
+        void resize (size_type size1, size_type size2, bool preserve = true) {
+            resize (BOOST_UBLAS_SAME (size1, size2), preserve);
+        }
+        BOOST_UBLAS_INLINE
+        void resize_packed_preserve (size_type size) {
+            size_ = BOOST_UBLAS_SAME (size, size);
+            data ().resize (triangular_type::packed_size (layout_type (), size_, size_), value_type ());
+        }
+
+        // Element access
+        BOOST_UBLAS_INLINE
+        const_reference operator () (size_type i, size_type j) const {
+            BOOST_UBLAS_CHECK (i < size_, bad_index ());
+            BOOST_UBLAS_CHECK (j < size_, bad_index ());
+            if (triangular_type::other (i, j))
+                return data () [triangular_type::element (layout_type (), i, size_, j, size_)];
+            else
+                return data () [triangular_type::element (layout_type (), j, size_, i, size_)];
+        }
+        BOOST_UBLAS_INLINE
+        reference at_element (size_type i, size_type j) {
+            BOOST_UBLAS_CHECK (i < size_, bad_index ());
+            BOOST_UBLAS_CHECK (j < size_, bad_index ());
+            return data () [triangular_type::element (layout_type (), i, size_, j, size_)];
+        }
+        BOOST_UBLAS_INLINE
+        reference operator () (size_type i, size_type j) {
+            BOOST_UBLAS_CHECK (i < size_, bad_index ());
+            BOOST_UBLAS_CHECK (j < size_, bad_index ());
+            if (triangular_type::other (i, j))
+                return data () [triangular_type::element (layout_type (), i, size_, j, size_)];
+            else
+                return data () [triangular_type::element (layout_type (), j, size_, i, size_)];
+        }
+
+        // Element assignment
+        BOOST_UBLAS_INLINE
+        reference insert_element (size_type i, size_type j, const_reference t) {
+            return (operator () (i, j) = t);
+        }
+        BOOST_UBLAS_INLINE
+        void erase_element (size_type i, size_type j) {
+            operator () (i, j) = value_type/*zero*/();
+        }
+        
+        // Zeroing
+        BOOST_UBLAS_INLINE
+        void clear () {
+            // data ().clear ();
+            std::fill (data ().begin (), data ().end (), value_type/*zero*/());
+        }
+
+        // Assignment
+        BOOST_UBLAS_INLINE
+        symmetric_matrix &operator = (const symmetric_matrix &m) {
+            size_ = m.size_;
+            data () = m.data ();
+            return *this;
+        }
+        BOOST_UBLAS_INLINE
+        symmetric_matrix &assign_temporary (symmetric_matrix &m) {
+            swap (m);
+            return *this;
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_matrix &operator = (const matrix_expression<AE> &ae) {
+            self_type temporary (ae);
+            return assign_temporary (temporary);
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_matrix &assign (const matrix_expression<AE> &ae) {
+            matrix_assign<scalar_assign> (*this, ae);
+            return *this;
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_matrix& operator += (const matrix_expression<AE> &ae) {
+            self_type temporary (*this + ae);
+            return assign_temporary (temporary);
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_matrix &plus_assign (const matrix_expression<AE> &ae) {
+            matrix_assign<scalar_plus_assign> (*this, ae);
+            return *this;
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_matrix& operator -= (const matrix_expression<AE> &ae) {
+            self_type temporary (*this - ae);
+            return assign_temporary (temporary);
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_matrix &minus_assign (const matrix_expression<AE> &ae) {
+            matrix_assign<scalar_minus_assign> (*this, ae);
+            return *this;
+        }
+        template<class AT>
+        BOOST_UBLAS_INLINE
+        symmetric_matrix& operator *= (const AT &at) {
+            matrix_assign_scalar<scalar_multiplies_assign> (*this, at);
+            return *this;
+        }
+        template<class AT>
+        BOOST_UBLAS_INLINE
+        symmetric_matrix& operator /= (const AT &at) {
+            matrix_assign_scalar<scalar_divides_assign> (*this, at);
+            return *this;
+        }
+
+        // Swapping
+        BOOST_UBLAS_INLINE
+        void swap (symmetric_matrix &m) {
+            if (this != &m) {
+                std::swap (size_, m.size_);
+                data ().swap (m.data ());
+            }
+        }
+        BOOST_UBLAS_INLINE
+        friend void swap (symmetric_matrix &m1, symmetric_matrix &m2) {
+            m1.swap (m2);
+        }
+
+        // Iterator types
+#ifdef BOOST_UBLAS_USE_INDEXED_ITERATOR
+        typedef indexed_iterator1<self_type, packed_random_access_iterator_tag> iterator1;
+        typedef indexed_iterator2<self_type, packed_random_access_iterator_tag> iterator2;
+        typedef indexed_const_iterator1<self_type, dense_random_access_iterator_tag> const_iterator1;
+        typedef indexed_const_iterator2<self_type, dense_random_access_iterator_tag> const_iterator2;
+#else
+        class const_iterator1;
+        class iterator1;
+        class const_iterator2;
+        class iterator2;
+#endif
+        typedef reverse_iterator_base1<const_iterator1> const_reverse_iterator1;
+        typedef reverse_iterator_base1<iterator1> reverse_iterator1;
+        typedef reverse_iterator_base2<const_iterator2> const_reverse_iterator2;
+        typedef reverse_iterator_base2<iterator2> reverse_iterator2;
+
+        // Element lookup
+        BOOST_UBLAS_INLINE
+        const_iterator1 find1 (int /* rank */, size_type i, size_type j) const {
+            return const_iterator1 (*this, i, j);
+        }
+        BOOST_UBLAS_INLINE
+        iterator1 find1 (int rank, size_type i, size_type j) {
+            if (rank == 1)
+                i = triangular_type::mutable_restrict1 (i, j);
+            return iterator1 (*this, i, j);
+        }
+        BOOST_UBLAS_INLINE
+        const_iterator2 find2 (int /* rank */, size_type i, size_type j) const {
+            return const_iterator2 (*this, i, j);
+        }
+        BOOST_UBLAS_INLINE
+        iterator2 find2 (int rank, size_type i, size_type j) {
+            if (rank == 1)
+                j = triangular_type::mutable_restrict2 (i, j);
+            return iterator2 (*this, i, j);
+        }
+
+        // Iterators simply are indices.
+
+#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
+        class const_iterator1:
+            public container_const_reference<symmetric_matrix>,
+            public random_access_iterator_base<dense_random_access_iterator_tag,
+                                               const_iterator1, value_type> {
+        public:
+            typedef typename symmetric_matrix::value_type value_type;
+            typedef typename symmetric_matrix::difference_type difference_type;
+            typedef typename symmetric_matrix::const_reference reference;
+            typedef const typename symmetric_matrix::pointer pointer;
+
+            typedef const_iterator2 dual_iterator_type;
+            typedef const_reverse_iterator2 dual_reverse_iterator_type;
+
+            // Construction and destruction
+            BOOST_UBLAS_INLINE
+            const_iterator1 ():
+                container_const_reference<self_type> (), it1_ (), it2_ () {}
+            BOOST_UBLAS_INLINE
+            const_iterator1 (const self_type &m, size_type it1, size_type it2):
+                container_const_reference<self_type> (m), it1_ (it1), it2_ (it2) {}
+            BOOST_UBLAS_INLINE
+            const_iterator1 (const iterator1 &it):
+                container_const_reference<self_type> (it ()), it1_ (it.it1_), it2_ (it.it2_) {}
+
+            // Arithmetic
+            BOOST_UBLAS_INLINE
+            const_iterator1 &operator ++ () {
+                ++ it1_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator1 &operator -- () {
+                -- it1_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator1 &operator += (difference_type n) {
+                it1_ += n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator1 &operator -= (difference_type n) {
+                it1_ -= n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            difference_type operator - (const const_iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it2_ == it.it2_, external_logic ());
+                return it1_ - it.it1_;
+            }
+
+            // Dereference
+            BOOST_UBLAS_INLINE
+            const_reference operator * () const {
+                return (*this) () (it1_, it2_);
+            }
+            BOOST_UBLAS_INLINE
+            const_reference operator [] (difference_type n) const {
+                return *(*this + n);
+            }
+
+#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_iterator2 begin () const {
+                return (*this) ().find2 (1, it1_, 0);
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_iterator2 end () const {
+                return (*this) ().find2 (1, it1_, (*this) ().size2 ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_reverse_iterator2 rbegin () const {
+                return const_reverse_iterator2 (end ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_reverse_iterator2 rend () const {
+                return const_reverse_iterator2 (begin ());
+            }
+#endif
+
+            // Indices
+            BOOST_UBLAS_INLINE
+            size_type index1 () const {
+                return it1_;
+            }
+            BOOST_UBLAS_INLINE
+            size_type index2 () const {
+                return it2_;
+            }
+
+            // Assignment
+            BOOST_UBLAS_INLINE
+            const_iterator1 &operator = (const const_iterator1 &it) {
+                container_const_reference<self_type>::assign (&it ());
+                it1_ = it.it1_;
+                it2_ = it.it2_;
+                return *this;
+            }
+
+            // Comparison
+            BOOST_UBLAS_INLINE
+            bool operator == (const const_iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it2_ == it.it2_, external_logic ());
+                return it1_ == it.it1_;
+            }
+            BOOST_UBLAS_INLINE
+            bool operator < (const const_iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it2_ == it.it2_, external_logic ());
+                return it1_ < it.it1_;
+            }
+
+        private:
+            size_type it1_;
+            size_type it2_;
+        };
+#endif
+
+        BOOST_UBLAS_INLINE
+        const_iterator1 begin1 () const {
+            return find1 (0, 0, 0);
+        }
+        BOOST_UBLAS_INLINE
+        const_iterator1 end1 () const {
+            return find1 (0, size_, 0);
+        }
+
+#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
+        class iterator1:
+            public container_reference<symmetric_matrix>,
+            public random_access_iterator_base<packed_random_access_iterator_tag,
+                                               iterator1, value_type> {
+        public:
+            typedef typename symmetric_matrix::value_type value_type;
+            typedef typename symmetric_matrix::difference_type difference_type;
+            typedef typename symmetric_matrix::reference reference;
+            typedef typename symmetric_matrix::pointer pointer;
+            typedef iterator2 dual_iterator_type;
+            typedef reverse_iterator2 dual_reverse_iterator_type;
+
+            // Construction and destruction
+            BOOST_UBLAS_INLINE
+            iterator1 ():
+                container_reference<self_type> (), it1_ (), it2_ () {}
+            BOOST_UBLAS_INLINE
+            iterator1 (self_type &m, size_type it1, size_type it2):
+                container_reference<self_type> (m), it1_ (it1), it2_ (it2) {}
+
+            // Arithmetic
+            BOOST_UBLAS_INLINE
+            iterator1 &operator ++ () {
+                ++ it1_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator1 &operator -- () {
+                -- it1_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator1 &operator += (difference_type n) {
+                it1_ += n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator1 &operator -= (difference_type n) {
+                it1_ -= n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            difference_type operator - (const iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it2_ == it.it2_, external_logic ());
+                return it1_ - it.it1_;
+            }
+
+            // Dereference
+            BOOST_UBLAS_INLINE
+            reference operator * () const {
+                return (*this) () (it1_, it2_);
+            }
+            BOOST_UBLAS_INLINE
+            reference operator [] (difference_type n) const {
+                return *(*this + n);
+            }
+
+#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            iterator2 begin () const {
+                return (*this) ().find2 (1, it1_, 0);
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            iterator2 end () const {
+                return (*this) ().find2 (1, it1_, (*this) ().size2 ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            reverse_iterator2 rbegin () const {
+                return reverse_iterator2 (end ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            reverse_iterator2 rend () const {
+                return reverse_iterator2 (begin ());
+            }
+#endif
+
+            // Indices
+            BOOST_UBLAS_INLINE
+            size_type index1 () const {
+                return it1_;
+            }
+            BOOST_UBLAS_INLINE
+            size_type index2 () const {
+                return it2_;
+            }
+
+            // Assignment
+            BOOST_UBLAS_INLINE
+            iterator1 &operator = (const iterator1 &it) {
+                container_reference<self_type>::assign (&it ());
+                it1_ = it.it1_;
+                it2_ = it.it2_;
+                return *this;
+            }
+
+            // Comparison
+            BOOST_UBLAS_INLINE
+            bool operator == (const iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it2_ == it.it2_, external_logic ());
+                return it1_ == it.it1_;
+            }
+            BOOST_UBLAS_INLINE
+            bool operator < (const iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it2_ == it.it2_, external_logic ());
+                return it1_ < it.it1_;
+            }
+
+        private:
+            size_type it1_;
+            size_type it2_;
+
+            friend class const_iterator1;
+        };
+#endif
+
+        BOOST_UBLAS_INLINE
+        iterator1 begin1 () {
+            return find1 (0, 0, 0);
+        }
+        BOOST_UBLAS_INLINE
+        iterator1 end1 () {
+            return find1 (0, size_, 0);
+        }
+
+#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
+        class const_iterator2:
+            public container_const_reference<symmetric_matrix>,
+            public random_access_iterator_base<dense_random_access_iterator_tag,
+                                               const_iterator2, value_type> {
+        public:
+            typedef typename symmetric_matrix::value_type value_type;
+            typedef typename symmetric_matrix::difference_type difference_type;
+            typedef typename symmetric_matrix::const_reference reference;
+            typedef const typename symmetric_matrix::pointer pointer;
+
+            typedef const_iterator1 dual_iterator_type;
+            typedef const_reverse_iterator1 dual_reverse_iterator_type;
+
+            // Construction and destruction
+            BOOST_UBLAS_INLINE
+            const_iterator2 ():
+                container_const_reference<self_type> (), it1_ (), it2_ () {}
+            BOOST_UBLAS_INLINE
+            const_iterator2 (const self_type &m, size_type it1, size_type it2):
+                container_const_reference<self_type> (m), it1_ (it1), it2_ (it2) {}
+            BOOST_UBLAS_INLINE
+            const_iterator2 (const iterator2 &it):
+                container_const_reference<self_type> (it ()), it1_ (it.it1_), it2_ (it.it2_) {}
+
+            // Arithmetic
+            BOOST_UBLAS_INLINE
+            const_iterator2 &operator ++ () {
+                ++ it2_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator2 &operator -- () {
+                -- it2_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator2 &operator += (difference_type n) {
+                it2_ += n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator2 &operator -= (difference_type n) {
+                it2_ -= n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            difference_type operator - (const const_iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it1_ == it.it1_, external_logic ());
+                return it2_ - it.it2_;
+            }
+
+            // Dereference
+            BOOST_UBLAS_INLINE
+            const_reference operator * () const {
+                return (*this) () (it1_, it2_);
+            }
+            BOOST_UBLAS_INLINE
+            const_reference operator [] (difference_type n) const {
+                return *(*this + n);
+            }
+
+#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_iterator1 begin () const {
+                return (*this) ().find1 (1, 0, it2_);
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_iterator1 end () const {
+                return (*this) ().find1 (1, (*this) ().size1 (), it2_);
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_reverse_iterator1 rbegin () const {
+                return const_reverse_iterator1 (end ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_reverse_iterator1 rend () const {
+                return const_reverse_iterator1 (begin ());
+            }
+#endif
+
+            // Indices
+            BOOST_UBLAS_INLINE
+            size_type index1 () const {
+                return it1_;
+            }
+            BOOST_UBLAS_INLINE
+            size_type index2 () const {
+                return it2_;
+            }
+
+            // Assignment
+            BOOST_UBLAS_INLINE
+            const_iterator2 &operator = (const const_iterator2 &it) {
+                container_const_reference<self_type>::assign (&it ());
+                it1_ = it.it1_;
+                it2_ = it.it2_;
+                return *this;
+            }
+
+            // Comparison
+            BOOST_UBLAS_INLINE
+            bool operator == (const const_iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it1_ == it.it1_, external_logic ());
+                return it2_ == it.it2_;
+            }
+            BOOST_UBLAS_INLINE
+            bool operator < (const const_iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it1_ == it.it1_, external_logic ());
+                return it2_ < it.it2_;
+            }
+
+        private:
+            size_type it1_;
+            size_type it2_;
+        };
+#endif
+
+        BOOST_UBLAS_INLINE
+        const_iterator2 begin2 () const {
+            return find2 (0, 0, 0);
+        }
+        BOOST_UBLAS_INLINE
+        const_iterator2 end2 () const {
+            return find2 (0, 0, size_);
+        }
+
+#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
+        class iterator2:
+            public container_reference<symmetric_matrix>,
+            public random_access_iterator_base<packed_random_access_iterator_tag,
+                                               iterator2, value_type> {
+        public:
+            typedef typename symmetric_matrix::value_type value_type;
+            typedef typename symmetric_matrix::difference_type difference_type;
+            typedef typename symmetric_matrix::reference reference;
+            typedef typename symmetric_matrix::pointer pointer;
+
+            typedef iterator1 dual_iterator_type;
+            typedef reverse_iterator1 dual_reverse_iterator_type;
+
+            // Construction and destruction
+            BOOST_UBLAS_INLINE
+            iterator2 ():
+                container_reference<self_type> (), it1_ (), it2_ () {}
+            BOOST_UBLAS_INLINE
+            iterator2 (self_type &m, size_type it1, size_type it2):
+                container_reference<self_type> (m), it1_ (it1), it2_ (it2) {}
+
+            // Arithmetic
+            BOOST_UBLAS_INLINE
+            iterator2 &operator ++ () {
+                ++ it2_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator2 &operator -- () {
+                -- it2_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator2 &operator += (difference_type n) {
+                it2_ += n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator2 &operator -= (difference_type n) {
+                it2_ -= n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            difference_type operator - (const iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it1_ == it.it1_, external_logic ());
+                return it2_ - it.it2_;
+            }
+
+            // Dereference
+            BOOST_UBLAS_INLINE
+            reference operator * () const {
+                return (*this) () (it1_, it2_);
+            }
+            BOOST_UBLAS_INLINE
+            reference operator [] (difference_type n) const {
+                return *(*this + n);
+            }
+
+#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            iterator1 begin () const {
+                return (*this) ().find1 (1, 0, it2_);
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            iterator1 end () const {
+                return (*this) ().find1 (1, (*this) ().size1 (), it2_);
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            reverse_iterator1 rbegin () const {
+                return reverse_iterator1 (end ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            reverse_iterator1 rend () const {
+                return reverse_iterator1 (begin ());
+            }
+#endif
+
+            // Indices
+            BOOST_UBLAS_INLINE
+            size_type index1 () const {
+                return it1_;
+            }
+            BOOST_UBLAS_INLINE
+            size_type index2 () const {
+                return it2_;
+            }
+
+            // Assignment
+            BOOST_UBLAS_INLINE
+            iterator2 &operator = (const iterator2 &it) {
+                container_reference<self_type>::assign (&it ());
+                it1_ = it.it1_;
+                it2_ = it.it2_;
+                return *this;
+            }
+
+            // Comparison
+            BOOST_UBLAS_INLINE
+            bool operator == (const iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it1_ == it.it1_, external_logic ());
+                return it2_ == it.it2_;
+            }
+            BOOST_UBLAS_INLINE
+            bool operator < (const iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (it1_ == it.it1_, external_logic ());
+                return it2_ < it.it2_;
+            }
+
+        private:
+            size_type it1_;
+            size_type it2_;
+
+            friend class const_iterator2;
+        };
+#endif
+
+        BOOST_UBLAS_INLINE
+        iterator2 begin2 () {
+            return find2 (0, 0, 0);
+        }
+        BOOST_UBLAS_INLINE
+        iterator2 end2 () {
+            return find2 (0, 0, size_);
+        }
+
+        // Reverse iterators
+
+        BOOST_UBLAS_INLINE
+        const_reverse_iterator1 rbegin1 () const {
+            return const_reverse_iterator1 (end1 ());
+        }
+        BOOST_UBLAS_INLINE
+        const_reverse_iterator1 rend1 () const {
+            return const_reverse_iterator1 (begin1 ());
+        }
+
+        BOOST_UBLAS_INLINE
+        reverse_iterator1 rbegin1 () {
+            return reverse_iterator1 (end1 ());
+        }
+        BOOST_UBLAS_INLINE
+        reverse_iterator1 rend1 () {
+            return reverse_iterator1 (begin1 ());
+        }
+
+        BOOST_UBLAS_INLINE
+        const_reverse_iterator2 rbegin2 () const {
+            return const_reverse_iterator2 (end2 ());
+        }
+        BOOST_UBLAS_INLINE
+        const_reverse_iterator2 rend2 () const {
+            return const_reverse_iterator2 (begin2 ());
+        }
+
+        BOOST_UBLAS_INLINE
+        reverse_iterator2 rbegin2 () {
+            return reverse_iterator2 (end2 ());
+        }
+        BOOST_UBLAS_INLINE
+        reverse_iterator2 rend2 () {
+            return reverse_iterator2 (begin2 ());
+        }
+
+    private:
+        size_type size_;
+        array_type data_;
+    };
+
+
+    // Symmetric matrix adaptor class
+    template<class M, class TRI>
+    class symmetric_adaptor:
+        public matrix_expression<symmetric_adaptor<M, TRI> > {
+
+        typedef symmetric_adaptor<M, TRI> self_type;
+    public:
+#ifdef BOOST_UBLAS_ENABLE_PROXY_SHORTCUTS
+        using matrix_expression<self_type>::operator ();
+#endif
+        typedef const M const_matrix_type;
+        typedef M matrix_type;
+        typedef TRI triangular_type;
+        typedef typename M::size_type size_type;
+        typedef typename M::difference_type difference_type;
+        typedef typename M::value_type value_type;
+        typedef typename M::const_reference const_reference;
+        typedef typename boost::mpl::if_<boost::is_const<M>,
+                                          typename M::const_reference,
+                                          typename M::reference>::type reference;
+        typedef typename boost::mpl::if_<boost::is_const<M>,
+                                          typename M::const_closure_type,
+                                          typename M::closure_type>::type matrix_closure_type;
+        typedef const self_type const_closure_type;
+        typedef self_type closure_type;
+        // Replaced by _temporary_traits to avoid type requirements on M
+        //typedef typename M::vector_temporary_type vector_temporary_type;
+        //typedef typename M::matrix_temporary_type matrix_temporary_type;
+        typedef typename storage_restrict_traits<typename M::storage_category,
+                                                 packed_proxy_tag>::storage_category storage_category;
+        typedef typename M::orientation_category orientation_category;
+
+        // Construction and destruction
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor (matrix_type &data):
+            matrix_expression<self_type> (),
+            data_ (data) {
+            BOOST_UBLAS_CHECK (data_.size1 () == data_.size2 (), bad_size ());
+        }
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor (const symmetric_adaptor &m):
+            matrix_expression<self_type> (),
+            data_ (m.data_) {
+            BOOST_UBLAS_CHECK (data_.size1 () == data_.size2 (), bad_size ());
+        }
+
+        // Accessors
+        BOOST_UBLAS_INLINE
+        size_type size1 () const {
+            return data_.size1 ();
+        }
+        BOOST_UBLAS_INLINE
+        size_type size2 () const {
+            return data_.size2 ();
+        }
+
+        // Storage accessors
+        BOOST_UBLAS_INLINE
+        const matrix_closure_type &data () const {
+            return data_;
+        }
+        BOOST_UBLAS_INLINE
+        matrix_closure_type &data () {
+            return data_;
+        }
+
+        // Element access
+#ifndef BOOST_UBLAS_PROXY_CONST_MEMBER
+        BOOST_UBLAS_INLINE
+        const_reference operator () (size_type i, size_type j) const {
+            BOOST_UBLAS_CHECK (i < size1 (), bad_index ());
+            BOOST_UBLAS_CHECK (j < size2 (), bad_index ());
+            if (triangular_type::other (i, j))
+                return data () (i, j);
+            else
+                return data () (j, i);
+        }
+        BOOST_UBLAS_INLINE
+        reference operator () (size_type i, size_type j) {
+            BOOST_UBLAS_CHECK (i < size1 (), bad_index ());
+            BOOST_UBLAS_CHECK (j < size2 (), bad_index ());
+            if (triangular_type::other (i, j))
+                return data () (i, j);
+            else
+                return data () (j, i);
+        }
+#else
+        BOOST_UBLAS_INLINE
+        reference operator () (size_type i, size_type j) const {
+            BOOST_UBLAS_CHECK (i < size1 (), bad_index ());
+            BOOST_UBLAS_CHECK (j < size2 (), bad_index ());
+            if (triangular_type::other (i, j))
+                return data () (i, j);
+            else
+                return data () (j, i);
+        }
+#endif
+
+        // Assignment
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor &operator = (const symmetric_adaptor &m) {
+            matrix_assign<scalar_assign, triangular_type> (*this, m);
+            return *this;
+        }
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor &assign_temporary (symmetric_adaptor &m) {
+            *this = m;
+            return *this;
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor &operator = (const matrix_expression<AE> &ae) {
+            matrix_assign<scalar_assign, triangular_type> (*this, matrix<value_type> (ae));
+            return *this;
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor &assign (const matrix_expression<AE> &ae) {
+            matrix_assign<scalar_assign, triangular_type> (*this, ae);
+            return *this;
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor& operator += (const matrix_expression<AE> &ae) {
+            matrix_assign<scalar_assign, triangular_type> (*this, matrix<value_type> (*this + ae));
+            return *this;
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor &plus_assign (const matrix_expression<AE> &ae) {
+            matrix_assign<scalar_plus_assign, triangular_type> (*this, ae);
+            return *this;
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor& operator -= (const matrix_expression<AE> &ae) {
+            matrix_assign<scalar_assign, triangular_type> (*this, matrix<value_type> (*this - ae));
+            return *this;
+        }
+        template<class AE>
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor &minus_assign (const matrix_expression<AE> &ae) {
+            matrix_assign<scalar_minus_assign, triangular_type> (*this, ae);
+            return *this;
+        }
+        template<class AT>
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor& operator *= (const AT &at) {
+            matrix_assign_scalar<scalar_multiplies_assign> (*this, at);
+            return *this;
+        }
+        template<class AT>
+        BOOST_UBLAS_INLINE
+        symmetric_adaptor& operator /= (const AT &at) {
+            matrix_assign_scalar<scalar_divides_assign> (*this, at);
+            return *this;
+        }
+
+        // Closure comparison
+        BOOST_UBLAS_INLINE
+        bool same_closure (const symmetric_adaptor &sa) const {
+            return (*this).data ().same_closure (sa.data ());
+       }
+
+        // Swapping
+        BOOST_UBLAS_INLINE
+        void swap (symmetric_adaptor &m) {
+            if (this != &m)
+                matrix_swap<scalar_swap, triangular_type> (*this, m);
+        }
+        BOOST_UBLAS_INLINE
+        friend void swap (symmetric_adaptor &m1, symmetric_adaptor &m2) {
+            m1.swap (m2);
+        }
+
+        // Iterator types
+    private:
+        // Use matrix iterator
+        typedef typename M::const_iterator1 const_subiterator1_type;
+        typedef typename boost::mpl::if_<boost::is_const<M>,
+                                          typename M::const_iterator1,
+                                          typename M::iterator1>::type subiterator1_type;
+        typedef typename M::const_iterator2 const_subiterator2_type;
+        typedef typename boost::mpl::if_<boost::is_const<M>,
+                                          typename M::const_iterator2,
+                                          typename M::iterator2>::type subiterator2_type;
+
+    public:
+#ifdef BOOST_UBLAS_USE_INDEXED_ITERATOR
+        typedef indexed_iterator1<self_type, packed_random_access_iterator_tag> iterator1;
+        typedef indexed_iterator2<self_type, packed_random_access_iterator_tag> iterator2;
+        typedef indexed_const_iterator1<self_type, dense_random_access_iterator_tag> const_iterator1;
+        typedef indexed_const_iterator2<self_type, dense_random_access_iterator_tag> const_iterator2;
+#else
+        class const_iterator1;
+        class iterator1;
+        class const_iterator2;
+        class iterator2;
+#endif
+        typedef reverse_iterator_base1<const_iterator1> const_reverse_iterator1;
+        typedef reverse_iterator_base1<iterator1> reverse_iterator1;
+        typedef reverse_iterator_base2<const_iterator2> const_reverse_iterator2;
+        typedef reverse_iterator_base2<iterator2> reverse_iterator2;
+
+        // Element lookup
+        BOOST_UBLAS_INLINE
+        const_iterator1 find1 (int rank, size_type i, size_type j) const {
+            if (triangular_type::other (i, j)) {
+                if (triangular_type::other (size1 (), j)) {
+                    return const_iterator1 (*this, 0, 0,
+                                            data ().find1 (rank, i, j), data ().find1 (rank, size1 (), j),
+                                            data ().find2 (rank, size2 (), size1 ()), data ().find2 (rank, size2 (), size1 ()));
+                } else {
+                    return const_iterator1 (*this, 0, 1,
+                                            data ().find1 (rank, i, j), data ().find1 (rank, j, j),
+                                            data ().find2 (rank, j, j), data ().find2 (rank, j, size1 ()));
+                }
+            } else {
+                if (triangular_type::other (size1 (), j)) {
+                    return const_iterator1 (*this, 1, 0,
+                                            data ().find1 (rank, j, j), data ().find1 (rank, size1 (), j),
+                                            data ().find2 (rank, j, i), data ().find2 (rank, j, j));
+                } else {
+                    return const_iterator1 (*this, 1, 1,
+                                            data ().find1 (rank, size1 (), size2 ()), data ().find1 (rank, size1 (), size2 ()),
+                                            data ().find2 (rank, j, i), data ().find2 (rank, j, size1 ()));
+                }
+            }
+        }
+        BOOST_UBLAS_INLINE
+        iterator1 find1 (int rank, size_type i, size_type j) {
+            if (rank == 1)
+                i = triangular_type::mutable_restrict1 (i, j);
+            return iterator1 (*this, data ().find1 (rank, i, j));
+        }
+        BOOST_UBLAS_INLINE
+        const_iterator2 find2 (int rank, size_type i, size_type j) const {
+            if (triangular_type::other (i, j)) {
+                if (triangular_type::other (i, size2 ())) {
+                    return const_iterator2 (*this, 1, 1,
+                                            data ().find1 (rank, size2 (), size1 ()), data ().find1 (rank, size2 (), size1 ()),
+                                            data ().find2 (rank, i, j), data ().find2 (rank, i, size2 ()));
+                } else {
+                    return const_iterator2 (*this, 1, 0,
+                                            data ().find1 (rank, i, i), data ().find1 (rank, size2 (), i),
+                                            data ().find2 (rank, i, j), data ().find2 (rank, i, i));
+                }
+            } else {
+                if (triangular_type::other (i, size2 ())) {
+                    return const_iterator2 (*this, 0, 1,
+                                            data ().find1 (rank, j, i), data ().find1 (rank, i, i),
+                                            data ().find2 (rank, i, i), data ().find2 (rank, i, size2 ()));
+                } else {
+                    return const_iterator2 (*this, 0, 0,
+                                            data ().find1 (rank, j, i), data ().find1 (rank, size2 (), i),
+                                            data ().find2 (rank, size1 (), size2 ()), data ().find2 (rank, size2 (), size2 ()));
+                }
+            }
+        }
+        BOOST_UBLAS_INLINE
+        iterator2 find2 (int rank, size_type i, size_type j) {
+            if (rank == 1)
+                j = triangular_type::mutable_restrict2 (i, j);
+            return iterator2 (*this, data ().find2 (rank, i, j));
+        }
+
+        // Iterators simply are indices.
+
+#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
+        class const_iterator1:
+            public container_const_reference<symmetric_adaptor>,
+            public random_access_iterator_base<typename iterator_restrict_traits<
+                                                   typename const_subiterator1_type::iterator_category, dense_random_access_iterator_tag>::iterator_category,
+                                               const_iterator1, value_type> {
+        public:
+            typedef typename const_subiterator1_type::value_type value_type;
+            typedef typename const_subiterator1_type::difference_type difference_type;
+            typedef typename const_subiterator1_type::reference reference;
+            typedef typename const_subiterator1_type::pointer pointer;
+
+            typedef const_iterator2 dual_iterator_type;
+            typedef const_reverse_iterator2 dual_reverse_iterator_type;
+
+            // Construction and destruction
+            BOOST_UBLAS_INLINE
+            const_iterator1 ():
+                container_const_reference<self_type> (),
+                begin_ (-1), end_ (-1), current_ (-1),
+                it1_begin_ (), it1_end_ (), it1_ (),
+                it2_begin_ (), it2_end_ (), it2_ () {}
+            BOOST_UBLAS_INLINE
+            const_iterator1 (const self_type &m, int begin, int end,
+                             const const_subiterator1_type &it1_begin, const const_subiterator1_type &it1_end,
+                             const const_subiterator2_type &it2_begin, const const_subiterator2_type &it2_end):
+                container_const_reference<self_type> (m),
+                begin_ (begin), end_ (end), current_ (begin),
+                it1_begin_ (it1_begin), it1_end_ (it1_end), it1_ (it1_begin_),
+                it2_begin_ (it2_begin), it2_end_ (it2_end), it2_ (it2_begin_) {
+                if (current_ == 0 && it1_ == it1_end_)
+                    current_ = 1;
+                if (current_ == 1 && it2_ == it2_end_)
+                    current_ = 0;
+                if ((current_ == 0 && it1_ == it1_end_) ||
+                    (current_ == 1 && it2_ == it2_end_))
+                    current_ = end_;
+                BOOST_UBLAS_CHECK (current_ == end_ ||
+                                   (current_ == 0 && it1_ != it1_end_) ||
+                                   (current_ == 1 && it2_ != it2_end_), internal_logic ());
+            }
+            // FIXME cannot compile
+            //  iterator1 does not have these members!
+            BOOST_UBLAS_INLINE
+            const_iterator1 (const iterator1 &it):
+                container_const_reference<self_type> (it ()),
+                begin_ (it.begin_), end_ (it.end_), current_ (it.current_),
+                it1_begin_ (it.it1_begin_), it1_end_ (it.it1_end_), it1_ (it.it1_),
+                it2_begin_ (it.it2_begin_), it2_end_ (it.it2_end_), it2_ (it.it2_) {
+                BOOST_UBLAS_CHECK (current_ == end_ ||
+                                   (current_ == 0 && it1_ != it1_end_) ||
+                                   (current_ == 1 && it2_ != it2_end_), internal_logic ());
+            }
+
+            // Arithmetic
+            BOOST_UBLAS_INLINE
+            const_iterator1 &operator ++ () {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    BOOST_UBLAS_CHECK (it1_ != it1_end_, internal_logic ());
+                    ++ it1_;
+                    if (it1_ == it1_end_ && end_ == 1) {
+                        it2_ = it2_begin_;
+                        current_ = 1;
+                    }
+                } else /* if (current_ == 1) */ {
+                    BOOST_UBLAS_CHECK (it2_ != it2_end_, internal_logic ());
+                    ++ it2_;
+                    if (it2_ == it2_end_ && end_ == 0) {
+                        it1_ = it1_begin_;
+                        current_ = 0;
+                    }
+                }
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator1 &operator -- () {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    if (it1_ == it1_begin_ && begin_ == 1) {
+                        it2_ = it2_end_;
+                        BOOST_UBLAS_CHECK (it2_ != it2_begin_, internal_logic ());
+                        -- it2_;
+                        current_ = 1;
+                    } else {
+                        -- it1_;
+                    }
+                } else /* if (current_ == 1) */ {
+                    if (it2_ == it2_begin_ && begin_ == 0) {
+                        it1_ = it1_end_;
+                        BOOST_UBLAS_CHECK (it1_ != it1_begin_, internal_logic ());
+                        -- it1_;
+                        current_ = 0;
+                    } else {
+                        -- it2_;
+                    }
+                }
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator1 &operator += (difference_type n) {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    size_type d = (std::min) (n, it1_end_ - it1_);
+                    it1_ += d;
+                    n -= d;
+                    if (n > 0 || (end_ == 1 && it1_ == it1_end_)) {
+                        BOOST_UBLAS_CHECK (end_ == 1, external_logic ());
+                        d = (std::min) (n, it2_end_ - it2_begin_);
+                        it2_ = it2_begin_ + d;
+                        n -= d;
+                        current_ = 1;
+                    }
+                } else /* if (current_ == 1) */ {
+                    size_type d = (std::min) (n, it2_end_ - it2_);
+                    it2_ += d;
+                    n -= d;
+                    if (n > 0 || (end_ == 0 && it2_ == it2_end_)) {
+                        BOOST_UBLAS_CHECK (end_ == 0, external_logic ());
+                        d = (std::min) (n, it1_end_ - it1_begin_);
+                        it1_ = it1_begin_ + d;
+                        n -= d;
+                        current_ = 0;
+                    }
+                }
+                BOOST_UBLAS_CHECK (n == 0, external_logic ());
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator1 &operator -= (difference_type n) {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    size_type d = (std::min) (n, it1_ - it1_begin_);
+                    it1_ -= d;
+                    n -= d;
+                    if (n > 0) {
+                        BOOST_UBLAS_CHECK (end_ == 1, external_logic ());
+                        d = (std::min) (n, it2_end_ - it2_begin_);
+                        it2_ = it2_end_ - d;
+                        n -= d;
+                        current_ = 1;
+                    }
+                } else /* if (current_ == 1) */ {
+                    size_type d = (std::min) (n, it2_ - it2_begin_);
+                    it2_ -= d;
+                    n -= d;
+                    if (n > 0) {
+                        BOOST_UBLAS_CHECK (end_ == 0, external_logic ());
+                        d = (std::min) (n, it1_end_ - it1_begin_);
+                        it1_ = it1_end_ - d;
+                        n -= d;
+                        current_ = 0;
+                    }
+                }
+                BOOST_UBLAS_CHECK (n == 0, external_logic ());
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            difference_type operator - (const const_iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                BOOST_UBLAS_CHECK (it.current_ == 0 || it.current_ == 1, internal_logic ());
+                BOOST_UBLAS_CHECK (/* begin_ == it.begin_ && */ end_ == it.end_, internal_logic ());
+                if (current_ == 0 && it.current_ == 0) {
+                    return it1_ - it.it1_;
+                } else if (current_ == 0 && it.current_ == 1) {
+                    if (end_ == 1 && it.end_ == 1) {
+                        return (it1_ - it.it1_end_) + (it.it2_begin_ - it.it2_);
+                    } else /* if (end_ == 0 && it.end_ == 0) */ {
+                        return (it1_ - it.it1_begin_) + (it.it2_end_ - it.it2_);
+                    }
+
+                } else if (current_ == 1 && it.current_ == 0) {
+                    if (end_ == 1 && it.end_ == 1) {
+                        return (it2_ - it.it2_begin_) + (it.it1_end_ - it.it1_);
+                    } else /* if (end_ == 0 && it.end_ == 0) */ {
+                        return (it2_ - it.it2_end_) + (it.it1_begin_ - it.it1_);
+                    }
+                }
+                /* current_ == 1 && it.current_ == 1 */ {
+                    return it2_ - it.it2_;
+                }
+            }
+
+            // Dereference
+            BOOST_UBLAS_INLINE
+            const_reference operator * () const {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    BOOST_UBLAS_CHECK (it1_ != it1_end_, internal_logic ());
+                    return *it1_;
+                } else /* if (current_ == 1) */ {
+                    BOOST_UBLAS_CHECK (it2_ != it2_end_, internal_logic ());
+                    return *it2_;
+                }
+            }
+            BOOST_UBLAS_INLINE
+            const_reference operator [] (difference_type n) const {
+                return *(*this + n);
+            }
+
+#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_iterator2 begin () const {
+                return (*this) ().find2 (1, index1 (), 0);
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_iterator2 end () const {
+                return (*this) ().find2 (1, index1 (), (*this) ().size2 ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_reverse_iterator2 rbegin () const {
+                return const_reverse_iterator2 (end ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_reverse_iterator2 rend () const {
+                return const_reverse_iterator2 (begin ());
+            }
+#endif
+
+            // Indices
+            BOOST_UBLAS_INLINE
+            size_type index1 () const {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    BOOST_UBLAS_CHECK (it1_ != it1_end_, internal_logic ());
+                    return it1_.index1 ();
+                } else /* if (current_ == 1) */ {
+                    BOOST_UBLAS_CHECK (it2_ != it2_end_, internal_logic ());
+                    return it2_.index2 ();
+                }
+            }
+            BOOST_UBLAS_INLINE
+            size_type index2 () const {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    BOOST_UBLAS_CHECK (it1_ != it1_end_, internal_logic ());
+                    return it1_.index2 ();
+                } else /* if (current_ == 1) */ {
+                    BOOST_UBLAS_CHECK (it2_ != it2_end_, internal_logic ());
+                    return it2_.index1 ();
+                }
+            }
+
+            // Assignment
+            BOOST_UBLAS_INLINE
+            const_iterator1 &operator = (const const_iterator1 &it) {
+                container_const_reference<self_type>::assign (&it ());
+                begin_ = it.begin_;
+                end_ = it.end_;
+                current_ = it.current_;
+                it1_begin_ = it.it1_begin_;
+                it1_end_ = it.it1_end_;
+                it1_ = it.it1_;
+                it2_begin_ = it.it2_begin_;
+                it2_end_ = it.it2_end_;
+                it2_ = it.it2_;
+                return *this;
+            }
+
+            // Comparison
+            BOOST_UBLAS_INLINE
+            bool operator == (const const_iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                BOOST_UBLAS_CHECK (it.current_ == 0 || it.current_ == 1, internal_logic ());
+                BOOST_UBLAS_CHECK (/* begin_ == it.begin_ && */ end_ == it.end_, internal_logic ());
+                return (current_ == 0 && it.current_ == 0 && it1_ == it.it1_) ||
+                       (current_ == 1 && it.current_ == 1 && it2_ == it.it2_);
+            }
+            BOOST_UBLAS_INLINE
+            bool operator < (const const_iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                return it - *this > 0;
+            }
+
+        private:
+            int begin_;
+            int end_;
+            int current_;
+            const_subiterator1_type it1_begin_;
+            const_subiterator1_type it1_end_;
+            const_subiterator1_type it1_;
+            const_subiterator2_type it2_begin_;
+            const_subiterator2_type it2_end_;
+            const_subiterator2_type it2_;
+        };
+#endif
+
+        BOOST_UBLAS_INLINE
+        const_iterator1 begin1 () const {
+            return find1 (0, 0, 0);
+        }
+        BOOST_UBLAS_INLINE
+        const_iterator1 end1 () const {
+            return find1 (0, size1 (), 0);
+        }
+
+#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
+        class iterator1:
+            public container_reference<symmetric_adaptor>,
+            public random_access_iterator_base<typename iterator_restrict_traits<
+                                                   typename subiterator1_type::iterator_category, packed_random_access_iterator_tag>::iterator_category,
+                                               iterator1, value_type> {
+        public:
+            typedef typename subiterator1_type::value_type value_type;
+            typedef typename subiterator1_type::difference_type difference_type;
+            typedef typename subiterator1_type::reference reference;
+            typedef typename subiterator1_type::pointer pointer;
+
+            typedef iterator2 dual_iterator_type;
+            typedef reverse_iterator2 dual_reverse_iterator_type;
+
+            // Construction and destruction
+            BOOST_UBLAS_INLINE
+            iterator1 ():
+                container_reference<self_type> (), it1_ () {}
+            BOOST_UBLAS_INLINE
+            iterator1 (self_type &m, const subiterator1_type &it1):
+                container_reference<self_type> (m), it1_ (it1) {}
+
+            // Arithmetic
+            BOOST_UBLAS_INLINE
+            iterator1 &operator ++ () {
+                ++ it1_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator1 &operator -- () {
+                -- it1_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator1 &operator += (difference_type n) {
+                it1_ += n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator1 &operator -= (difference_type n) {
+                it1_ -= n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            difference_type operator - (const iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                return it1_ - it.it1_;
+            }
+
+            // Dereference
+            BOOST_UBLAS_INLINE
+            reference operator * () const {
+                return *it1_;
+            }
+            BOOST_UBLAS_INLINE
+            reference operator [] (difference_type n) const {
+                return *(*this + n);
+            }
+
+#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            iterator2 begin () const {
+                return (*this) ().find2 (1, index1 (), 0);
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            iterator2 end () const {
+                return (*this) ().find2 (1, index1 (), (*this) ().size2 ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            reverse_iterator2 rbegin () const {
+                return reverse_iterator2 (end ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            reverse_iterator2 rend () const {
+                return reverse_iterator2 (begin ());
+            }
+#endif
+
+            // Indices
+            BOOST_UBLAS_INLINE
+            size_type index1 () const {
+                return it1_.index1 ();
+            }
+            BOOST_UBLAS_INLINE
+            size_type index2 () const {
+                return it1_.index2 ();
+            }
+
+            // Assignment
+            BOOST_UBLAS_INLINE
+            iterator1 &operator = (const iterator1 &it) {
+                container_reference<self_type>::assign (&it ());
+                it1_ = it.it1_;
+                return *this;
+            }
+
+            // Comparison
+            BOOST_UBLAS_INLINE
+            bool operator == (const iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                return it1_ == it.it1_;
+            }
+            BOOST_UBLAS_INLINE
+            bool operator < (const iterator1 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                return it1_ < it.it1_;
+            }
+
+        private:
+            subiterator1_type it1_;
+
+            friend class const_iterator1;
+        };
+#endif
+
+        BOOST_UBLAS_INLINE
+        iterator1 begin1 () {
+            return find1 (0, 0, 0);
+        }
+        BOOST_UBLAS_INLINE
+        iterator1 end1 () {
+            return find1 (0, size1 (), 0);
+        }
+
+#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
+        class const_iterator2:
+            public container_const_reference<symmetric_adaptor>,
+            public random_access_iterator_base<typename iterator_restrict_traits<
+                                                   typename const_subiterator2_type::iterator_category, dense_random_access_iterator_tag>::iterator_category,
+                                               const_iterator2, value_type> {
+        public:
+            typedef typename const_subiterator2_type::value_type value_type;
+            typedef typename const_subiterator2_type::difference_type difference_type;
+            typedef typename const_subiterator2_type::reference reference;
+            typedef typename const_subiterator2_type::pointer pointer;
+
+            typedef const_iterator1 dual_iterator_type;
+            typedef const_reverse_iterator1 dual_reverse_iterator_type;
+
+            // Construction and destruction
+            BOOST_UBLAS_INLINE
+            const_iterator2 ():
+                container_const_reference<self_type> (),
+                begin_ (-1), end_ (-1), current_ (-1),
+                it1_begin_ (), it1_end_ (), it1_ (),
+                it2_begin_ (), it2_end_ (), it2_ () {}
+            BOOST_UBLAS_INLINE
+            const_iterator2 (const self_type &m, int begin, int end,
+                             const const_subiterator1_type &it1_begin, const const_subiterator1_type &it1_end,
+                             const const_subiterator2_type &it2_begin, const const_subiterator2_type &it2_end):
+                container_const_reference<self_type> (m),
+                begin_ (begin), end_ (end), current_ (begin),
+                it1_begin_ (it1_begin), it1_end_ (it1_end), it1_ (it1_begin_),
+                it2_begin_ (it2_begin), it2_end_ (it2_end), it2_ (it2_begin_) {
+                if (current_ == 0 && it1_ == it1_end_)
+                    current_ = 1;
+                if (current_ == 1 && it2_ == it2_end_)
+                    current_ = 0;
+                if ((current_ == 0 && it1_ == it1_end_) ||
+                    (current_ == 1 && it2_ == it2_end_))
+                    current_ = end_;
+                BOOST_UBLAS_CHECK (current_ == end_ ||
+                                   (current_ == 0 && it1_ != it1_end_) ||
+                                   (current_ == 1 && it2_ != it2_end_), internal_logic ());
+            }
+            // FIXME cannot compiler
+            //  iterator2 does not have these members!
+            BOOST_UBLAS_INLINE
+            const_iterator2 (const iterator2 &it):
+                container_const_reference<self_type> (it ()),
+                begin_ (it.begin_), end_ (it.end_), current_ (it.current_),
+                it1_begin_ (it.it1_begin_), it1_end_ (it.it1_end_), it1_ (it.it1_),
+                it2_begin_ (it.it2_begin_), it2_end_ (it.it2_end_), it2_ (it.it2_) {
+                BOOST_UBLAS_CHECK (current_ == end_ ||
+                                   (current_ == 0 && it1_ != it1_end_) ||
+                                   (current_ == 1 && it2_ != it2_end_), internal_logic ());
+            }
+
+            // Arithmetic
+            BOOST_UBLAS_INLINE
+            const_iterator2 &operator ++ () {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    BOOST_UBLAS_CHECK (it1_ != it1_end_, internal_logic ());
+                    ++ it1_;
+                    if (it1_ == it1_end_ && end_ == 1) {
+                        it2_ = it2_begin_;
+                        current_ = 1;
+                    }
+                } else /* if (current_ == 1) */ {
+                    BOOST_UBLAS_CHECK (it2_ != it2_end_, internal_logic ());
+                    ++ it2_;
+                    if (it2_ == it2_end_ && end_ == 0) {
+                        it1_ = it1_begin_;
+                        current_ = 0;
+                    }
+                }
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator2 &operator -- () {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    if (it1_ == it1_begin_ && begin_ == 1) {
+                        it2_ = it2_end_;
+                        BOOST_UBLAS_CHECK (it2_ != it2_begin_, internal_logic ());
+                        -- it2_;
+                        current_ = 1;
+                    } else {
+                        -- it1_;
+                    }
+                } else /* if (current_ == 1) */ {
+                    if (it2_ == it2_begin_ && begin_ == 0) {
+                        it1_ = it1_end_;
+                        BOOST_UBLAS_CHECK (it1_ != it1_begin_, internal_logic ());
+                        -- it1_;
+                        current_ = 0;
+                    } else {
+                        -- it2_;
+                    }
+                }
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator2 &operator += (difference_type n) {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    size_type d = (std::min) (n, it1_end_ - it1_);
+                    it1_ += d;
+                    n -= d;
+                    if (n > 0 || (end_ == 1 && it1_ == it1_end_)) {
+                        BOOST_UBLAS_CHECK (end_ == 1, external_logic ());
+                        d = (std::min) (n, it2_end_ - it2_begin_);
+                        it2_ = it2_begin_ + d;
+                        n -= d;
+                        current_ = 1;
+                    }
+                } else /* if (current_ == 1) */ {
+                    size_type d = (std::min) (n, it2_end_ - it2_);
+                    it2_ += d;
+                    n -= d;
+                    if (n > 0 || (end_ == 0 && it2_ == it2_end_)) {
+                        BOOST_UBLAS_CHECK (end_ == 0, external_logic ());
+                        d = (std::min) (n, it1_end_ - it1_begin_);
+                        it1_ = it1_begin_ + d;
+                        n -= d;
+                        current_ = 0;
+                    }
+                }
+                BOOST_UBLAS_CHECK (n == 0, external_logic ());
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            const_iterator2 &operator -= (difference_type n) {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    size_type d = (std::min) (n, it1_ - it1_begin_);
+                    it1_ -= d;
+                    n -= d;
+                    if (n > 0) {
+                        BOOST_UBLAS_CHECK (end_ == 1, external_logic ());
+                        d = (std::min) (n, it2_end_ - it2_begin_);
+                        it2_ = it2_end_ - d;
+                        n -= d;
+                        current_ = 1;
+                    }
+                } else /* if (current_ == 1) */ {
+                    size_type d = (std::min) (n, it2_ - it2_begin_);
+                    it2_ -= d;
+                    n -= d;
+                    if (n > 0) {
+                        BOOST_UBLAS_CHECK (end_ == 0, external_logic ());
+                        d = (std::min) (n, it1_end_ - it1_begin_);
+                        it1_ = it1_end_ - d;
+                        n -= d;
+                        current_ = 0;
+                    }
+                }
+                BOOST_UBLAS_CHECK (n == 0, external_logic ());
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            difference_type operator - (const const_iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                BOOST_UBLAS_CHECK (it.current_ == 0 || it.current_ == 1, internal_logic ());
+                BOOST_UBLAS_CHECK (/* begin_ == it.begin_ && */ end_ == it.end_, internal_logic ());
+                if (current_ == 0 && it.current_ == 0) {
+                    return it1_ - it.it1_;
+                } else if (current_ == 0 && it.current_ == 1) {
+                    if (end_ == 1 && it.end_ == 1) {
+                        return (it1_ - it.it1_end_) + (it.it2_begin_ - it.it2_);
+                    } else /* if (end_ == 0 && it.end_ == 0) */ {
+                        return (it1_ - it.it1_begin_) + (it.it2_end_ - it.it2_);
+                    }
+
+                } else if (current_ == 1 && it.current_ == 0) {
+                    if (end_ == 1 && it.end_ == 1) {
+                        return (it2_ - it.it2_begin_) + (it.it1_end_ - it.it1_);
+                    } else /* if (end_ == 0 && it.end_ == 0) */ {
+                        return (it2_ - it.it2_end_) + (it.it1_begin_ - it.it1_);
+                    }
+                }
+                /* current_ == 1 && it.current_ == 1 */ {
+                    return it2_ - it.it2_;
+                }
+            }
+
+            // Dereference
+            BOOST_UBLAS_INLINE
+            const_reference operator * () const {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    BOOST_UBLAS_CHECK (it1_ != it1_end_, internal_logic ());
+                    return *it1_;
+                } else /* if (current_ == 1) */ {
+                    BOOST_UBLAS_CHECK (it2_ != it2_end_, internal_logic ());
+                    return *it2_;
+                }
+            }
+            BOOST_UBLAS_INLINE
+            const_reference operator [] (difference_type n) const {
+                return *(*this + n);
+            }
+
+#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_iterator1 begin () const {
+                return (*this) ().find1 (1, 0, index2 ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_iterator1 end () const {
+                return (*this) ().find1 (1, (*this) ().size1 (), index2 ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_reverse_iterator1 rbegin () const {
+                return const_reverse_iterator1 (end ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            const_reverse_iterator1 rend () const {
+                return const_reverse_iterator1 (begin ());
+            }
+#endif
+
+            // Indices
+            BOOST_UBLAS_INLINE
+            size_type index1 () const {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    BOOST_UBLAS_CHECK (it1_ != it1_end_, internal_logic ());
+                    return it1_.index2 ();
+                } else /* if (current_ == 1) */ {
+                    BOOST_UBLAS_CHECK (it2_ != it2_end_, internal_logic ());
+                    return it2_.index1 ();
+                }
+            }
+            BOOST_UBLAS_INLINE
+            size_type index2 () const {
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                if (current_ == 0) {
+                    BOOST_UBLAS_CHECK (it1_ != it1_end_, internal_logic ());
+                    return it1_.index1 ();
+                } else /* if (current_ == 1) */ {
+                    BOOST_UBLAS_CHECK (it2_ != it2_end_, internal_logic ());
+                    return it2_.index2 ();
+                }
+            }
+
+            // Assignment
+            BOOST_UBLAS_INLINE
+            const_iterator2 &operator = (const const_iterator2 &it) {
+                container_const_reference<self_type>::assign (&it ());
+                begin_ = it.begin_;
+                end_ = it.end_;
+                current_ = it.current_;
+                it1_begin_ = it.it1_begin_;
+                it1_end_ = it.it1_end_;
+                it1_ = it.it1_;
+                it2_begin_ = it.it2_begin_;
+                it2_end_ = it.it2_end_;
+                it2_ = it.it2_;
+                return *this;
+            }
+
+            // Comparison
+            BOOST_UBLAS_INLINE
+            bool operator == (const const_iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                BOOST_UBLAS_CHECK (current_ == 0 || current_ == 1, internal_logic ());
+                BOOST_UBLAS_CHECK (it.current_ == 0 || it.current_ == 1, internal_logic ());
+                BOOST_UBLAS_CHECK (/* begin_ == it.begin_ && */ end_ == it.end_, internal_logic ());
+                return (current_ == 0 && it.current_ == 0 && it1_ == it.it1_) ||
+                       (current_ == 1 && it.current_ == 1 && it2_ == it.it2_);
+            }
+            BOOST_UBLAS_INLINE
+            bool operator < (const const_iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                return it - *this > 0;
+            }
+
+        private:
+            int begin_;
+            int end_;
+            int current_;
+            const_subiterator1_type it1_begin_;
+            const_subiterator1_type it1_end_;
+            const_subiterator1_type it1_;
+            const_subiterator2_type it2_begin_;
+            const_subiterator2_type it2_end_;
+            const_subiterator2_type it2_;
+        };
+#endif
+
+        BOOST_UBLAS_INLINE
+        const_iterator2 begin2 () const {
+            return find2 (0, 0, 0);
+        }
+        BOOST_UBLAS_INLINE
+        const_iterator2 end2 () const {
+            return find2 (0, 0, size2 ());
+        }
+
+#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
+        class iterator2:
+            public container_reference<symmetric_adaptor>,
+            public random_access_iterator_base<typename iterator_restrict_traits<
+                                                   typename subiterator2_type::iterator_category, packed_random_access_iterator_tag>::iterator_category,
+                                               iterator2, value_type> {
+        public:
+            typedef typename subiterator2_type::value_type value_type;
+            typedef typename subiterator2_type::difference_type difference_type;
+            typedef typename subiterator2_type::reference reference;
+            typedef typename subiterator2_type::pointer pointer;
+
+            typedef iterator1 dual_iterator_type;
+            typedef reverse_iterator1 dual_reverse_iterator_type;
+
+            // Construction and destruction
+            BOOST_UBLAS_INLINE
+            iterator2 ():
+                container_reference<self_type> (), it2_ () {}
+            BOOST_UBLAS_INLINE
+            iterator2 (self_type &m, const subiterator2_type &it2):
+                container_reference<self_type> (m), it2_ (it2) {}
+
+            // Arithmetic
+            BOOST_UBLAS_INLINE
+            iterator2 &operator ++ () {
+                ++ it2_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator2 &operator -- () {
+                -- it2_;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator2 &operator += (difference_type n) {
+                it2_ += n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            iterator2 &operator -= (difference_type n) {
+                it2_ -= n;
+                return *this;
+            }
+            BOOST_UBLAS_INLINE
+            difference_type operator - (const iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                return it2_ - it.it2_;
+            }
+
+            // Dereference
+            BOOST_UBLAS_INLINE
+            reference operator * () const {
+                return *it2_;
+            }
+            BOOST_UBLAS_INLINE
+            reference operator [] (difference_type n) const {
+                return *(*this + n);
+            }
+
+#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            iterator1 begin () const {
+                return (*this) ().find1 (1, 0, index2 ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            iterator1 end () const {
+                return (*this) ().find1 (1, (*this) ().size1 (), index2 ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            reverse_iterator1 rbegin () const {
+                return reverse_iterator1 (end ());
+            }
+            BOOST_UBLAS_INLINE
+#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
+            typename self_type::
+#endif
+            reverse_iterator1 rend () const {
+                return reverse_iterator1 (begin ());
+            }
+#endif
+
+            // Indices
+            BOOST_UBLAS_INLINE
+            size_type index1 () const {
+                return it2_.index1 ();
+            }
+            BOOST_UBLAS_INLINE
+            size_type index2 () const {
+                return it2_.index2 ();
+            }
+
+            // Assignment
+            BOOST_UBLAS_INLINE
+            iterator2 &operator = (const iterator2 &it) {
+                container_reference<self_type>::assign (&it ());
+                it2_ = it.it2_;
+                return *this;
+            }
+
+            // Comparison
+            BOOST_UBLAS_INLINE
+            bool operator == (const iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                return it2_ == it.it2_;
+            }
+            BOOST_UBLAS_INLINE
+            bool operator < (const iterator2 &it) const {
+                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
+                return it2_ < it.it2_;
+            }
+
+        private:
+            subiterator2_type it2_;
+
+            friend class const_iterator2;
+        };
+#endif
+
+        BOOST_UBLAS_INLINE
+        iterator2 begin2 () {
+            return find2 (0, 0, 0);
+        }
+        BOOST_UBLAS_INLINE
+        iterator2 end2 () {
+            return find2 (0, 0, size2 ());
+        }
+
+        // Reverse iterators
+
+        BOOST_UBLAS_INLINE
+        const_reverse_iterator1 rbegin1 () const {
+            return const_reverse_iterator1 (end1 ());
+        }
+        BOOST_UBLAS_INLINE
+        const_reverse_iterator1 rend1 () const {
+            return const_reverse_iterator1 (begin1 ());
+        }
+
+        BOOST_UBLAS_INLINE
+        reverse_iterator1 rbegin1 () {
+            return reverse_iterator1 (end1 ());
+        }
+        BOOST_UBLAS_INLINE
+        reverse_iterator1 rend1 () {
+            return reverse_iterator1 (begin1 ());
+        }
+
+        BOOST_UBLAS_INLINE
+        const_reverse_iterator2 rbegin2 () const {
+            return const_reverse_iterator2 (end2 ());
+        }
+        BOOST_UBLAS_INLINE
+        const_reverse_iterator2 rend2 () const {
+            return const_reverse_iterator2 (begin2 ());
+        }
+
+        BOOST_UBLAS_INLINE
+        reverse_iterator2 rbegin2 () {
+            return reverse_iterator2 (end2 ());
+        }
+        BOOST_UBLAS_INLINE
+        reverse_iterator2 rend2 () {
+            return reverse_iterator2 (begin2 ());
+        }
+
+    private:
+        matrix_closure_type data_;
+    };
+
+    // Specialization for temporary_traits
+    template <class M, class TRI>
+    struct vector_temporary_traits< symmetric_adaptor<M, TRI> >
+    : vector_temporary_traits< M > {} ;
+    template <class M, class TRI>
+    struct vector_temporary_traits< const symmetric_adaptor<M, TRI> >
+    : vector_temporary_traits< M > {} ;
+
+    template <class M, class TRI>
+    struct matrix_temporary_traits< symmetric_adaptor<M, TRI> >
+    : matrix_temporary_traits< M > {} ;
+    template <class M, class TRI>
+    struct matrix_temporary_traits< const symmetric_adaptor<M, TRI> >
+    : matrix_temporary_traits< M > {} ;
+
+}}}
+
+#endif