text: //
  //  Copyright (c) 2000-2002
  //  Joerg Walter, Mathias Koch
  //
  //  Distributed under the Boost Software License, Version 1.0. (See
  //  accompanying file LICENSE_1_0.txt or copy at
  //  http://www.boost.org/LICENSE_1_0.txt)
  //
  //  The authors gratefully acknowledge the support of
  //  GeNeSys mbH & Co. KG in producing this work.
  //
  
  #ifndef _BOOST_UBLAS_MATRIX_ASSIGN_
  #define _BOOST_UBLAS_MATRIX_ASSIGN_
  
  #include <boost/numeric/ublas/traits.hpp>
  // Required for make_conformant storage
  #include <vector>
  
  // Iterators based on ideas of Jeremy Siek
  
  namespace boost { namespace numeric { namespace ublas {
  namespace detail {
      
      // Weak equality check - useful to compare equality two arbitary matrix expression results.
      // Since the actual expressions are unknown, we check for and arbitary error bound
      // on the relative error.
      // For a linear expression the infinity norm makes sense as we do not know how the elements will be
      // combined in the expression. False positive results are inevitable for arbirary expressions!
      template<class E1, class E2, class S>
      BOOST_UBLAS_INLINE
      bool equals (const matrix_expression<E1> &e1, const matrix_expression<E2> &e2, S epsilon, S min_norm) {
          return norm_inf (e1 - e2) < epsilon *
                 std::max<S> (std::max<S> (norm_inf (e1), norm_inf (e2)), min_norm);
      }
  
      template<class E1, class E2>
      BOOST_UBLAS_INLINE
      bool expression_type_check (const matrix_expression<E1> &e1, const matrix_expression<E2> &e2) {
          typedef typename type_traits<typename promote_traits<typename E1::value_type,
                                       typename E2::value_type>::promote_type>::real_type real_type;
          return equals (e1, e2, BOOST_UBLAS_TYPE_CHECK_EPSILON, BOOST_UBLAS_TYPE_CHECK_MIN);
      }
  
  
      template<class M, class E, class R>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void make_conformant (M &m, const matrix_expression<E> &e, row_major_tag, R) {
          BOOST_UBLAS_CHECK (m.size1 () == e ().size1 (), bad_size ());
          BOOST_UBLAS_CHECK (m.size2 () == e ().size2 (), bad_size ());
          typedef R conformant_restrict_type;
          typedef typename M::size_type size_type;
          typedef typename M::difference_type difference_type;
          typedef typename M::value_type value_type;
          // FIXME unbounded_array with push_back maybe better
          std::vector<std::pair<size_type, size_type> > index;
          typename M::iterator1 it1 (m.begin1 ());
          typename M::iterator1 it1_end (m.end1 ());
          typename E::const_iterator1 it1e (e ().begin1 ());
          typename E::const_iterator1 it1e_end (e ().end1 ());
          while (it1 != it1_end && it1e != it1e_end) {
              difference_type compare = it1.index1 () - it1e.index1 ();
              if (compare == 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename M::iterator2 it2 (it1.begin ());
                  typename M::iterator2 it2_end (it1.end ());
                  typename E::const_iterator2 it2e (it1e.begin ());
                  typename E::const_iterator2 it2e_end (it1e.end ());
  #else
                  typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
                  typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
                  typename E::const_iterator2 it2e (begin (it1e, iterator1_tag ()));
                  typename E::const_iterator2 it2e_end (end (it1e, iterator1_tag ()));
  #endif
                  if (it2 != it2_end && it2e != it2e_end) {
                      size_type it2_index = it2.index2 (), it2e_index = it2e.index2 ();
                      while (true) {
                          difference_type compare2 = it2_index - it2e_index;
                          if (compare2 == 0) {
                              ++ it2, ++ it2e;
                              if (it2 != it2_end && it2e != it2e_end) {
                                  it2_index = it2.index2 ();
                                  it2e_index = it2e.index2 ();
                              } else
                                  break;
                          } else if (compare2 < 0) {
                              increment (it2, it2_end, - compare2);
                              if (it2 != it2_end)
                                  it2_index = it2.index2 ();
                              else
                                  break;
                          } else if (compare2 > 0) {
                              if (conformant_restrict_type::other (it2e.index1 (), it2e.index2 ()))
                                  if (static_cast<value_type>(*it2e) != value_type/*zero*/())
                                      index.push_back (std::pair<size_type, size_type> (it2e.index1 (), it2e.index2 ()));
                              ++ it2e;
                              if (it2e != it2e_end)
                                  it2e_index = it2e.index2 ();
                              else
                                  break;
                          }
                      }
                  }
                  while (it2e != it2e_end) {
                      if (conformant_restrict_type::other (it2e.index1 (), it2e.index2 ()))
                          if (static_cast<value_type>(*it2e) != value_type/*zero*/())
                              index.push_back (std::pair<size_type, size_type> (it2e.index1 (), it2e.index2 ()));
                      ++ it2e;
                  }
                  ++ it1, ++ it1e;
              } else if (compare < 0) {
                  increment (it1, it1_end, - compare);
              } else if (compare > 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename E::const_iterator2 it2e (it1e.begin ());
                  typename E::const_iterator2 it2e_end (it1e.end ());
  #else
                  typename E::const_iterator2 it2e (begin (it1e, iterator1_tag ()));
                  typename E::const_iterator2 it2e_end (end (it1e, iterator1_tag ()));
  #endif
                  while (it2e != it2e_end) {
                      if (conformant_restrict_type::other (it2e.index1 (), it2e.index2 ()))
                          if (static_cast<value_type>(*it2e) != value_type/*zero*/())
                              index.push_back (std::pair<size_type, size_type> (it2e.index1 (), it2e.index2 ()));
                      ++ it2e;
                  }
                  ++ it1e;
              }
          }
          while (it1e != it1e_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename E::const_iterator2 it2e (it1e.begin ());
              typename E::const_iterator2 it2e_end (it1e.end ());
  #else
              typename E::const_iterator2 it2e (begin (it1e, iterator1_tag ()));
              typename E::const_iterator2 it2e_end (end (it1e, iterator1_tag ()));
  #endif
              while (it2e != it2e_end) {
                  if (conformant_restrict_type::other (it2e.index1 (), it2e.index2 ()))
                      if (static_cast<value_type>(*it2e) != value_type/*zero*/())
                          index.push_back (std::pair<size_type, size_type> (it2e.index1 (), it2e.index2 ()));
                  ++ it2e;
              }
              ++ it1e;
          }
          // ISSUE proxies require insert_element
          for (size_type k = 0; k < index.size (); ++ k)
              m (index [k].first, index [k].second) = value_type/*zero*/();
      }
      template<class M, class E, class R>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void make_conformant (M &m, const matrix_expression<E> &e, column_major_tag, R) {
          BOOST_UBLAS_CHECK (m.size1 () == e ().size1 (), bad_size ());
          BOOST_UBLAS_CHECK (m.size2 () == e ().size2 (), bad_size ());
          typedef R conformant_restrict_type;
          typedef typename M::size_type size_type;
          typedef typename M::difference_type difference_type;
          typedef typename M::value_type value_type;
          std::vector<std::pair<size_type, size_type> > index;
          typename M::iterator2 it2 (m.begin2 ());
          typename M::iterator2 it2_end (m.end2 ());
          typename E::const_iterator2 it2e (e ().begin2 ());
          typename E::const_iterator2 it2e_end (e ().end2 ());
          while (it2 != it2_end && it2e != it2e_end) {
              difference_type compare = it2.index2 () - it2e.index2 ();
              if (compare == 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename M::iterator1 it1 (it2.begin ());
                  typename M::iterator1 it1_end (it2.end ());
                  typename E::const_iterator1 it1e (it2e.begin ());
                  typename E::const_iterator1 it1e_end (it2e.end ());
  #else
                  typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
                  typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
                  typename E::const_iterator1 it1e (begin (it2e, iterator2_tag ()));
                  typename E::const_iterator1 it1e_end (end (it2e, iterator2_tag ()));
  #endif
                  if (it1 != it1_end && it1e != it1e_end) {
                      size_type it1_index = it1.index1 (), it1e_index = it1e.index1 ();
                      while (true) {
                          difference_type compare2 = it1_index - it1e_index;
                          if (compare2 == 0) {
                              ++ it1, ++ it1e;
                              if (it1 != it1_end && it1e != it1e_end) {
                                  it1_index = it1.index1 ();
                                  it1e_index = it1e.index1 ();
                              } else
                                  break;
                          } else if (compare2 < 0) {
                              increment (it1, it1_end, - compare2);
                              if (it1 != it1_end)
                                  it1_index = it1.index1 ();
                              else
                                  break;
                          } else if (compare2 > 0) {
                              if (conformant_restrict_type::other (it1e.index1 (), it1e.index2 ()))
                                  if (static_cast<value_type>(*it1e) != value_type/*zero*/())
                                      index.push_back (std::pair<size_type, size_type> (it1e.index1 (), it1e.index2 ()));
                              ++ it1e;
                              if (it1e != it1e_end)
                                  it1e_index = it1e.index1 ();
                              else
                                  break;
                          }
                      }
                  }
                  while (it1e != it1e_end) {
                      if (conformant_restrict_type::other (it1e.index1 (), it1e.index2 ()))
                          if (static_cast<value_type>(*it1e) != value_type/*zero*/())
                              index.push_back (std::pair<size_type, size_type> (it1e.index1 (), it1e.index2 ()));
                      ++ it1e;
                  }
                  ++ it2, ++ it2e;
              } else if (compare < 0) {
                  increment (it2, it2_end, - compare);
              } else if (compare > 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename E::const_iterator1 it1e (it2e.begin ());
                  typename E::const_iterator1 it1e_end (it2e.end ());
  #else
                  typename E::const_iterator1 it1e (begin (it2e, iterator2_tag ()));
                  typename E::const_iterator1 it1e_end (end (it2e, iterator2_tag ()));
  #endif
                  while (it1e != it1e_end) {
                      if (conformant_restrict_type::other (it1e.index1 (), it1e.index2 ()))
                          if (static_cast<value_type>(*it1e) != value_type/*zero*/())
                              index.push_back (std::pair<size_type, size_type> (it1e.index1 (), it1e.index2 ()));
                      ++ it1e;
                  }
                  ++ it2e;
              }
          }
          while (it2e != it2e_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename E::const_iterator1 it1e (it2e.begin ());
              typename E::const_iterator1 it1e_end (it2e.end ());
  #else
              typename E::const_iterator1 it1e (begin (it2e, iterator2_tag ()));
              typename E::const_iterator1 it1e_end (end (it2e, iterator2_tag ()));
  #endif
              while (it1e != it1e_end) {
                  if (conformant_restrict_type::other (it1e.index1 (), it1e.index2 ()))
                      if (static_cast<value_type>(*it1e) != value_type/*zero*/())
                          index.push_back (std::pair<size_type, size_type> (it1e.index1 (), it1e.index2 ()));
                  ++ it1e;
              }
              ++ it2e;
          }
          // ISSUE proxies require insert_element
          for (size_type k = 0; k < index.size (); ++ k)
              m (index [k].first, index [k].second) = value_type/*zero*/();
      }
  
  }//namespace detail
  
  
      // Explicitly iterating row major
      template<template <class T1, class T2> class F, class M, class T>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void iterating_matrix_assign_scalar (M &m, const T &t, row_major_tag) {
          typedef F<typename M::iterator2::reference, T> functor_type;
          typedef typename M::difference_type difference_type;
          difference_type size1 (m.size1 ());
          difference_type size2 (m.size2 ());
          typename M::iterator1 it1 (m.begin1 ());
          BOOST_UBLAS_CHECK (size2 == 0 || m.end1 () - it1 == size1, bad_size ());
          while (-- size1 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator2 it2 (it1.begin ());
  #else
              typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
  #endif
              BOOST_UBLAS_CHECK (it1.end () - it2 == size2, bad_size ());
              difference_type temp_size2 (size2);
  #ifndef BOOST_UBLAS_USE_DUFF_DEVICE
              while (-- temp_size2 >= 0)
                  functor_type::apply (*it2, t), ++ it2;
  #else
              DD (temp_size2, 4, r, (functor_type::apply (*it2, t), ++ it2));
  #endif
              ++ it1;
          }
      }
      // Explicitly iterating column major
      template<template <class T1, class T2> class F, class M, class T>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void iterating_matrix_assign_scalar (M &m, const T &t, column_major_tag) {
          typedef F<typename M::iterator1::reference, T> functor_type;
          typedef typename M::difference_type difference_type;
          difference_type size2 (m.size2 ());
          difference_type size1 (m.size1 ());
          typename M::iterator2 it2 (m.begin2 ());
          BOOST_UBLAS_CHECK (size1 == 0 || m.end2 () - it2 == size2, bad_size ());
          while (-- size2 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator1 it1 (it2.begin ());
  #else
              typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
  #endif
              BOOST_UBLAS_CHECK (it2.end () - it1 == size1, bad_size ());
              difference_type temp_size1 (size1);
  #ifndef BOOST_UBLAS_USE_DUFF_DEVICE
              while (-- temp_size1 >= 0)
                  functor_type::apply (*it1, t), ++ it1;
  #else
              DD (temp_size1, 4, r, (functor_type::apply (*it1, t), ++ it1));
  #endif
              ++ it2;
          }
      }
      // Explicitly indexing row major
      template<template <class T1, class T2> class F, class M, class T>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void indexing_matrix_assign_scalar (M &m, const T &t, row_major_tag) {
          typedef F<typename M::reference, T> functor_type;
          typedef typename M::size_type size_type;
          size_type size1 (m.size1 ());
          size_type size2 (m.size2 ());
          for (size_type i = 0; i < size1; ++ i) {
  #ifndef BOOST_UBLAS_USE_DUFF_DEVICE
              for (size_type j = 0; j < size2; ++ j)
                  functor_type::apply (m (i, j), t);
  #else
              size_type j (0);
              DD (size2, 4, r, (functor_type::apply (m (i, j), t), ++ j));
  #endif
          }
      }
      // Explicitly indexing column major
      template<template <class T1, class T2> class F, class M, class T>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void indexing_matrix_assign_scalar (M &m, const T &t, column_major_tag) {
          typedef F<typename M::reference, T> functor_type;
          typedef typename M::size_type size_type;
          size_type size2 (m.size2 ());
          size_type size1 (m.size1 ());
          for (size_type j = 0; j < size2; ++ j) {
  #ifndef BOOST_UBLAS_USE_DUFF_DEVICE
              for (size_type i = 0; i < size1; ++ i)
                  functor_type::apply (m (i, j), t);
  #else
              size_type i (0);
              DD (size1, 4, r, (functor_type::apply (m (i, j), t), ++ i));
  #endif
          }
      }
  
      // Dense (proxy) case
      template<template <class T1, class T2> class F, class M, class T, class C>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign_scalar (M &m, const T &t, dense_proxy_tag, C) {
          typedef C orientation_category;
  #ifdef BOOST_UBLAS_USE_INDEXING
          indexing_matrix_assign_scalar<F> (m, t, orientation_category ());
  #elif BOOST_UBLAS_USE_ITERATING
          iterating_matrix_assign_scalar<F> (m, t, orientation_category ());
  #else
          typedef typename M::size_type size_type;
          size_type size1 (m.size1 ());
          size_type size2 (m.size2 ());
          if (size1 >= BOOST_UBLAS_ITERATOR_THRESHOLD &&
              size2 >= BOOST_UBLAS_ITERATOR_THRESHOLD)
              iterating_matrix_assign_scalar<F> (m, t, orientation_category ());
          else
              indexing_matrix_assign_scalar<F> (m, t, orientation_category ());
  #endif
      }
      // Packed (proxy) row major case
      template<template <class T1, class T2> class F, class M, class T>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign_scalar (M &m, const T &t, packed_proxy_tag, row_major_tag) {
          typedef F<typename M::iterator2::reference, T> functor_type;
          typedef typename M::difference_type difference_type;
          typename M::iterator1 it1 (m.begin1 ());
          difference_type size1 (m.end1 () - it1);
          while (-- size1 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator2 it2 (it1.begin ());
              difference_type size2 (it1.end () - it2);
  #else
              typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
              difference_type size2 (end (it1, iterator1_tag ()) - it2);
  #endif
              while (-- size2 >= 0)
                  functor_type::apply (*it2, t), ++ it2;
              ++ it1;
          }
      }
      // Packed (proxy) column major case
      template<template <class T1, class T2> class F, class M, class T>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign_scalar (M &m, const T &t, packed_proxy_tag, column_major_tag) {
          typedef F<typename M::iterator1::reference, T> functor_type;
          typedef typename M::difference_type difference_type;
          typename M::iterator2 it2 (m.begin2 ());
          difference_type size2 (m.end2 () - it2);
          while (-- size2 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator1 it1 (it2.begin ());
              difference_type size1 (it2.end () - it1);
  #else
              typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
              difference_type size1 (end (it2, iterator2_tag ()) - it1);
  #endif
              while (-- size1 >= 0)
                  functor_type::apply (*it1, t), ++ it1;
              ++ it2;
          }
      }
      // Sparse (proxy) row major case
      template<template <class T1, class T2> class F, class M, class T>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign_scalar (M &m, const T &t, sparse_proxy_tag, row_major_tag) {
          typedef F<typename M::iterator2::reference, T> functor_type;
          typename M::iterator1 it1 (m.begin1 ());
          typename M::iterator1 it1_end (m.end1 ());
          while (it1 != it1_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator2 it2 (it1.begin ());
              typename M::iterator2 it2_end (it1.end ());
  #else
              typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
              typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
  #endif
              while (it2 != it2_end)
                  functor_type::apply (*it2, t), ++ it2;
              ++ it1;
          }
      }
      // Sparse (proxy) column major case
      template<template <class T1, class T2> class F, class M, class T>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign_scalar (M &m, const T &t, sparse_proxy_tag, column_major_tag) {
          typedef F<typename M::iterator1::reference, T> functor_type;
          typename M::iterator2 it2 (m.begin2 ());
          typename M::iterator2 it2_end (m.end2 ());
          while (it2 != it2_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator1 it1 (it2.begin ());
              typename M::iterator1 it1_end (it2.end ());
  #else
              typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
              typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
  #endif
              while (it1 != it1_end)
                  functor_type::apply (*it1, t), ++ it1;
              ++ it2;
          }
      }
  
      // Dispatcher
      template<template <class T1, class T2> class F, class M, class T>
      BOOST_UBLAS_INLINE
      void matrix_assign_scalar (M &m, const T &t) {
          typedef typename M::storage_category storage_category;
          typedef typename M::orientation_category orientation_category;
          matrix_assign_scalar<F> (m, t, storage_category (), orientation_category ());
      }
  
      template<class SC, bool COMPUTED, class RI1, class RI2>
      struct matrix_assign_traits {
          typedef SC storage_category;
      };
  
      template<bool COMPUTED>
      struct matrix_assign_traits<dense_tag, COMPUTED, packed_random_access_iterator_tag, packed_random_access_iterator_tag> {
          typedef packed_tag storage_category;
      };
      template<>
      struct matrix_assign_traits<dense_tag, false, sparse_bidirectional_iterator_tag, sparse_bidirectional_iterator_tag> {
          typedef sparse_tag storage_category;
      };
      template<>
      struct matrix_assign_traits<dense_tag, true, sparse_bidirectional_iterator_tag, sparse_bidirectional_iterator_tag> {
          typedef sparse_proxy_tag storage_category;
      };
  
      template<bool COMPUTED>
      struct matrix_assign_traits<dense_proxy_tag, COMPUTED, packed_random_access_iterator_tag, packed_random_access_iterator_tag> {
          typedef packed_proxy_tag storage_category;
      };
      template<bool COMPUTED>
      struct matrix_assign_traits<dense_proxy_tag, COMPUTED, sparse_bidirectional_iterator_tag, sparse_bidirectional_iterator_tag> {
          typedef sparse_proxy_tag storage_category;
      };
  
      template<>
      struct matrix_assign_traits<packed_tag, false, sparse_bidirectional_iterator_tag, sparse_bidirectional_iterator_tag> {
          typedef sparse_tag storage_category;
      };
      template<>
      struct matrix_assign_traits<packed_tag, true, sparse_bidirectional_iterator_tag, sparse_bidirectional_iterator_tag> {
          typedef sparse_proxy_tag storage_category;
      };
  
      template<bool COMPUTED>
      struct matrix_assign_traits<packed_proxy_tag, COMPUTED, sparse_bidirectional_iterator_tag, sparse_bidirectional_iterator_tag> {
          typedef sparse_proxy_tag storage_category;
      };
  
      template<>
      struct matrix_assign_traits<sparse_tag, true, dense_random_access_iterator_tag, dense_random_access_iterator_tag> {
          typedef sparse_proxy_tag storage_category;
      };
      template<>
      struct matrix_assign_traits<sparse_tag, true, packed_random_access_iterator_tag, packed_random_access_iterator_tag> {
          typedef sparse_proxy_tag storage_category;
      };
      template<>
      struct matrix_assign_traits<sparse_tag, true, sparse_bidirectional_iterator_tag, sparse_bidirectional_iterator_tag> {
          typedef sparse_proxy_tag storage_category;
      };
  
      // Explicitly iterating row major
      template<template <class T1, class T2> class F, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void iterating_matrix_assign (M &m, const matrix_expression<E> &e, row_major_tag) {
          typedef F<typename M::iterator2::reference, typename E::value_type> functor_type;
          typedef typename M::difference_type difference_type;
          difference_type size1 (BOOST_UBLAS_SAME (m.size1 (), e ().size1 ()));
          difference_type size2 (BOOST_UBLAS_SAME (m.size2 (), e ().size2 ()));
          typename M::iterator1 it1 (m.begin1 ());
          BOOST_UBLAS_CHECK (size2 == 0 || m.end1 () - it1 == size1, bad_size ());
          typename E::const_iterator1 it1e (e ().begin1 ());
          BOOST_UBLAS_CHECK (size2 == 0 || e ().end1 () - it1e == size1, bad_size ());
          while (-- size1 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator2 it2 (it1.begin ());
              typename E::const_iterator2 it2e (it1e.begin ());
  #else
              typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
              typename E::const_iterator2 it2e (begin (it1e, iterator1_tag ()));
  #endif
              BOOST_UBLAS_CHECK (it1.end () - it2 == size2, bad_size ());
              BOOST_UBLAS_CHECK (it1e.end () - it2e == size2, bad_size ());
              difference_type temp_size2 (size2);
  #ifndef BOOST_UBLAS_USE_DUFF_DEVICE
              while (-- temp_size2 >= 0)
                  functor_type::apply (*it2, *it2e), ++ it2, ++ it2e;
  #else
              DD (temp_size2, 2, r, (functor_type::apply (*it2, *it2e), ++ it2, ++ it2e));
  #endif
              ++ it1, ++ it1e;
          }
      }
      // Explicitly iterating column major
      template<template <class T1, class T2> class F, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void iterating_matrix_assign (M &m, const matrix_expression<E> &e, column_major_tag) {
          typedef F<typename M::iterator1::reference, typename E::value_type> functor_type;
          typedef typename M::difference_type difference_type;
          difference_type size2 (BOOST_UBLAS_SAME (m.size2 (), e ().size2 ()));
          difference_type size1 (BOOST_UBLAS_SAME (m.size1 (), e ().size1 ()));
          typename M::iterator2 it2 (m.begin2 ());
          BOOST_UBLAS_CHECK (size1 == 0 || m.end2 () - it2 == size2, bad_size ());
          typename E::const_iterator2 it2e (e ().begin2 ());
          BOOST_UBLAS_CHECK (size1 == 0 || e ().end2 () - it2e == size2, bad_size ());
          while (-- size2 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator1 it1 (it2.begin ());
              typename E::const_iterator1 it1e (it2e.begin ());
  #else
              typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
              typename E::const_iterator1 it1e (begin (it2e, iterator2_tag ()));
  #endif
              BOOST_UBLAS_CHECK (it2.end () - it1 == size1, bad_size ());
              BOOST_UBLAS_CHECK (it2e.end () - it1e == size1, bad_size ());
              difference_type temp_size1 (size1);
  #ifndef BOOST_UBLAS_USE_DUFF_DEVICE
              while (-- temp_size1 >= 0)
                  functor_type::apply (*it1, *it1e), ++ it1, ++ it1e;
  #else
              DD (temp_size1, 2, r, (functor_type::apply (*it1, *it1e), ++ it1, ++ it1e));
  #endif
              ++ it2, ++ it2e;
          }
      }
      // Explicitly indexing row major
      template<template <class T1, class T2> class F, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void indexing_matrix_assign (M &m, const matrix_expression<E> &e, row_major_tag) {
          typedef F<typename M::reference, typename E::value_type> functor_type;
          typedef typename M::size_type size_type;
          size_type size1 (BOOST_UBLAS_SAME (m.size1 (), e ().size1 ()));
          size_type size2 (BOOST_UBLAS_SAME (m.size2 (), e ().size2 ()));
          for (size_type i = 0; i < size1; ++ i) {
  #ifndef BOOST_UBLAS_USE_DUFF_DEVICE
              for (size_type j = 0; j < size2; ++ j)
                  functor_type::apply (m (i, j), e () (i, j));
  #else
              size_type j (0);
              DD (size2, 2, r, (functor_type::apply (m (i, j), e () (i, j)), ++ j));
  #endif
          }
      }
      // Explicitly indexing column major
      template<template <class T1, class T2> class F, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void indexing_matrix_assign (M &m, const matrix_expression<E> &e, column_major_tag) {
          typedef F<typename M::reference, typename E::value_type> functor_type;
          typedef typename M::size_type size_type;
          size_type size2 (BOOST_UBLAS_SAME (m.size2 (), e ().size2 ()));
          size_type size1 (BOOST_UBLAS_SAME (m.size1 (), e ().size1 ()));
          for (size_type j = 0; j < size2; ++ j) {
  #ifndef BOOST_UBLAS_USE_DUFF_DEVICE
              for (size_type i = 0; i < size1; ++ i)
                  functor_type::apply (m (i, j), e () (i, j));
  #else
              size_type i (0);
              DD (size1, 2, r, (functor_type::apply (m (i, j), e () (i, j)), ++ i));
  #endif
          }
      }
  
      // Dense (proxy) case
      template<template <class T1, class T2> class F, class R, class M, class E, class C>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign (M &m, const matrix_expression<E> &e, dense_proxy_tag, C) {
          // R unnecessary, make_conformant not required
          typedef C orientation_category;
  #ifdef BOOST_UBLAS_USE_INDEXING
          indexing_matrix_assign<F> (m, e, orientation_category ());
  #elif BOOST_UBLAS_USE_ITERATING
          iterating_matrix_assign<F> (m, e, orientation_category ());
  #else
          typedef typename M::difference_type difference_type;
          size_type size1 (BOOST_UBLAS_SAME (m.size1 (), e ().size1 ()));
          size_type size2 (BOOST_UBLAS_SAME (m.size2 (), e ().size2 ()));
          if (size1 >= BOOST_UBLAS_ITERATOR_THRESHOLD &&
              size2 >= BOOST_UBLAS_ITERATOR_THRESHOLD)
              iterating_matrix_assign<F> (m, e, orientation_category ());
          else
              indexing_matrix_assign<F> (m, e, orientation_category ());
  #endif
      }
      // Packed (proxy) row major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign (M &m, const matrix_expression<E> &e, packed_proxy_tag, row_major_tag) {
          typedef typename matrix_traits<E>::value_type expr_value_type;
          typedef F<typename M::iterator2::reference, expr_value_type> functor_type;
          // R unnecessary, make_conformant not required
          typedef typename M::difference_type difference_type;
  
          BOOST_UBLAS_CHECK (m.size1 () == e ().size1 (), bad_size ());
          BOOST_UBLAS_CHECK (m.size2 () == e ().size2 (), bad_size ());
  
  #if BOOST_UBLAS_TYPE_CHECK
          typedef typename M::value_type value_type;
          matrix<value_type, row_major> cm (m.size1 (), m.size2 ());
          indexing_matrix_assign<scalar_assign> (cm, m, row_major_tag ());
          indexing_matrix_assign<F> (cm, e, row_major_tag ());
  #endif
          typename M::iterator1 it1 (m.begin1 ());
          typename M::iterator1 it1_end (m.end1 ());
          typename E::const_iterator1 it1e (e ().begin1 ());
          typename E::const_iterator1 it1e_end (e ().end1 ());
          difference_type it1_size (it1_end - it1);
          difference_type it1e_size (it1e_end - it1e);
          difference_type diff1 (0);
          if (it1_size > 0 && it1e_size > 0)
              diff1 = it1.index1 () - it1e.index1 ();
          if (diff1 != 0) {
              difference_type size1 = (std::min) (diff1, it1e_size);
              if (size1 > 0) {
                  it1e += size1;
                  it1e_size -= size1;
                  diff1 -= size1;
              }
              size1 = (std::min) (- diff1, it1_size);
              if (size1 > 0) {
                  it1_size -= size1;
                  if (!functor_type::computed) {
                      while (-- size1 >= 0) { // zeroing
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                          typename M::iterator2 it2 (it1.begin ());
                          typename M::iterator2 it2_end (it1.end ());
  #else
                          typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
                          typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
  #endif
                          difference_type size2 (it2_end - it2);
                          while (-- size2 >= 0)
                              functor_type::apply (*it2, expr_value_type/*zero*/()), ++ it2;
                          ++ it1;
                      }
                  } else {
                      it1 += size1;
                  }
                  diff1 += size1;
              }
          }
          difference_type size1 ((std::min) (it1_size, it1e_size));
          it1_size -= size1;
          it1e_size -= size1;
          while (-- size1 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator2 it2 (it1.begin ());
              typename M::iterator2 it2_end (it1.end ());
              typename E::const_iterator2 it2e (it1e.begin ());
              typename E::const_iterator2 it2e_end (it1e.end ());
  #else
              typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
              typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
              typename E::const_iterator2 it2e (begin (it1e, iterator1_tag ()));
              typename E::const_iterator2 it2e_end (end (it1e, iterator1_tag ()));
  #endif
              difference_type it2_size (it2_end - it2);
              difference_type it2e_size (it2e_end - it2e);
              difference_type diff2 (0);
              if (it2_size > 0 && it2e_size > 0) {
                  diff2 = it2.index2 () - it2e.index2 ();
                  difference_type size2 = (std::min) (diff2, it2e_size);
                  if (size2 > 0) {
                      it2e += size2;
                      it2e_size -= size2;
                      diff2 -= size2;
                  }
                  size2 = (std::min) (- diff2, it2_size);
                  if (size2 > 0) {
                      it2_size -= size2;
                      if (!functor_type::computed) {
                          while (-- size2 >= 0)   // zeroing
                              functor_type::apply (*it2, expr_value_type/*zero*/()), ++ it2;
                      } else {
                          it2 += size2;
                      }
                      diff2 += size2;
                  }
              }
              difference_type size2 ((std::min) (it2_size, it2e_size));
              it2_size -= size2;
              it2e_size -= size2;
              while (-- size2 >= 0)
                  functor_type::apply (*it2, *it2e), ++ it2, ++ it2e;
              size2 = it2_size;
              if (!functor_type::computed) {
                  while (-- size2 >= 0)   // zeroing
                      functor_type::apply (*it2, expr_value_type/*zero*/()), ++ it2;
              } else {
                  it2 += size2;
              }
              ++ it1, ++ it1e;
          }
          size1 = it1_size;
          if (!functor_type::computed) {
              while (-- size1 >= 0) { // zeroing
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename M::iterator2 it2 (it1.begin ());
                  typename M::iterator2 it2_end (it1.end ());
  #else
                  typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
                  typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
  #endif
                  difference_type size2 (it2_end - it2);
                  while (-- size2 >= 0)
                      functor_type::apply (*it2, expr_value_type/*zero*/()), ++ it2;
                  ++ it1;
              }
          } else {
              it1 += size1;
          }
  #if BOOST_UBLAS_TYPE_CHECK
          if (! disable_type_check<bool>::value)
              BOOST_UBLAS_CHECK (detail::expression_type_check (m, cm), external_logic ());
  #endif
      }
      // Packed (proxy) column major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign (M &m, const matrix_expression<E> &e, packed_proxy_tag, column_major_tag) {
          typedef typename matrix_traits<E>::value_type expr_value_type;
          typedef F<typename M::iterator1::reference, expr_value_type> functor_type;
          // R unnecessary, make_conformant not required
          typedef typename M::difference_type difference_type;
  
          BOOST_UBLAS_CHECK (m.size2 () == e ().size2 (), bad_size ());
          BOOST_UBLAS_CHECK (m.size1 () == e ().size1 (), bad_size ());
  
  #if BOOST_UBLAS_TYPE_CHECK
          typedef typename M::value_type value_type;
          matrix<value_type, column_major> cm (m.size1 (), m.size2 ());
          indexing_matrix_assign<scalar_assign> (cm, m, column_major_tag ());
          indexing_matrix_assign<F> (cm, e, column_major_tag ());
  #endif
          typename M::iterator2 it2 (m.begin2 ());
          typename M::iterator2 it2_end (m.end2 ());
          typename E::const_iterator2 it2e (e ().begin2 ());
          typename E::const_iterator2 it2e_end (e ().end2 ());
          difference_type it2_size (it2_end - it2);
          difference_type it2e_size (it2e_end - it2e);
          difference_type diff2 (0);
          if (it2_size > 0 && it2e_size > 0)
              diff2 = it2.index2 () - it2e.index2 ();
          if (diff2 != 0) {
              difference_type size2 = (std::min) (diff2, it2e_size);
              if (size2 > 0) {
                  it2e += size2;
                  it2e_size -= size2;
                  diff2 -= size2;
              }
              size2 = (std::min) (- diff2, it2_size);
              if (size2 > 0) {
                  it2_size -= size2;
                  if (!functor_type::computed) {
                      while (-- size2 >= 0) { // zeroing
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                          typename M::iterator1 it1 (it2.begin ());
                          typename M::iterator1 it1_end (it2.end ());
  #else
                          typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
                          typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
  #endif
                          difference_type size1 (it1_end - it1);
                          while (-- size1 >= 0)
                              functor_type::apply (*it1, expr_value_type/*zero*/()), ++ it1;
                          ++ it2;
                      }
                  } else {
                      it2 += size2;
                  }
                  diff2 += size2;
              }
          }
          difference_type size2 ((std::min) (it2_size, it2e_size));
          it2_size -= size2;
          it2e_size -= size2;
          while (-- size2 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator1 it1 (it2.begin ());
              typename M::iterator1 it1_end (it2.end ());
              typename E::const_iterator1 it1e (it2e.begin ());
              typename E::const_iterator1 it1e_end (it2e.end ());
  #else
              typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
              typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
              typename E::const_iterator1 it1e (begin (it2e, iterator2_tag ()));
              typename E::const_iterator1 it1e_end (end (it2e, iterator2_tag ()));
  #endif
              difference_type it1_size (it1_end - it1);
              difference_type it1e_size (it1e_end - it1e);
              difference_type diff1 (0);
              if (it1_size > 0 && it1e_size > 0) {
                  diff1 = it1.index1 () - it1e.index1 ();
                  difference_type size1 = (std::min) (diff1, it1e_size);
                  if (size1 > 0) {
                      it1e += size1;
                      it1e_size -= size1;
                      diff1 -= size1;
                  }
                  size1 = (std::min) (- diff1, it1_size);
                  if (size1 > 0) {
                      it1_size -= size1;
                      if (!functor_type::computed) {
                          while (-- size1 >= 0)   // zeroing
                              functor_type::apply (*it1, expr_value_type/*zero*/()), ++ it1;
                      } else {
                          it1 += size1;
                      }
                      diff1 += size1;
                  }
              }
              difference_type size1 ((std::min) (it1_size, it1e_size));
              it1_size -= size1;
              it1e_size -= size1;
              while (-- size1 >= 0)
                  functor_type::apply (*it1, *it1e), ++ it1, ++ it1e;
              size1 = it1_size;
              if (!functor_type::computed) {
                  while (-- size1 >= 0)   // zeroing
                      functor_type::apply (*it1, expr_value_type/*zero*/()), ++ it1;
              } else {
                  it1 += size1;
              }
              ++ it2, ++ it2e;
          }
          size2 = it2_size;
          if (!functor_type::computed) {
              while (-- size2 >= 0) { // zeroing
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename M::iterator1 it1 (it2.begin ());
                  typename M::iterator1 it1_end (it2.end ());
  #else
                  typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
                  typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
  #endif
                  difference_type size1 (it1_end - it1);
                  while (-- size1 >= 0)
                      functor_type::apply (*it1, expr_value_type/*zero*/()), ++ it1;
                  ++ it2;
              }
          } else {
              it2 += size2;
          }
  #if BOOST_UBLAS_TYPE_CHECK
          if (! disable_type_check<bool>::value)
              BOOST_UBLAS_CHECK (detail::expression_type_check (m, cm), external_logic ());
  #endif
      }
      // Sparse row major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign (M &m, const matrix_expression<E> &e, sparse_tag, row_major_tag) {
          typedef F<typename M::iterator2::reference, typename E::value_type> functor_type;
          // R unnecessary, make_conformant not required
          BOOST_STATIC_ASSERT ((!functor_type::computed));
          BOOST_UBLAS_CHECK (m.size1 () == e ().size1 (), bad_size ());
          BOOST_UBLAS_CHECK (m.size2 () == e ().size2 (), bad_size ());
          typedef typename M::value_type value_type;
          // Sparse type has no numeric constraints to check
  
          m.clear ();
          typename E::const_iterator1 it1e (e ().begin1 ());
          typename E::const_iterator1 it1e_end (e ().end1 ());
          while (it1e != it1e_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename E::const_iterator2 it2e (it1e.begin ());
              typename E::const_iterator2 it2e_end (it1e.end ());
  #else
              typename E::const_iterator2 it2e (begin (it1e, iterator1_tag ()));
              typename E::const_iterator2 it2e_end (end (it1e, iterator1_tag ()));
  #endif
              while (it2e != it2e_end) {
                  value_type t (*it2e);
                  if (t != value_type/*zero*/())
                      m.insert_element (it2e.index1 (), it2e.index2 (), t);
                  ++ it2e;
              }
              ++ it1e;
          }
      }
      // Sparse column major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign (M &m, const matrix_expression<E> &e, sparse_tag, column_major_tag) {
          typedef F<typename M::iterator1::reference, typename E::value_type> functor_type;
          // R unnecessary, make_conformant not required
          BOOST_STATIC_ASSERT ((!functor_type::computed));
          BOOST_UBLAS_CHECK (m.size1 () == e ().size1 (), bad_size ());
          BOOST_UBLAS_CHECK (m.size2 () == e ().size2 (), bad_size ());
          typedef typename M::value_type value_type;
          // Sparse type has no numeric constraints to check
  
          m.clear ();
          typename E::const_iterator2 it2e (e ().begin2 ());
          typename E::const_iterator2 it2e_end (e ().end2 ());
          while (it2e != it2e_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename E::const_iterator1 it1e (it2e.begin ());
              typename E::const_iterator1 it1e_end (it2e.end ());
  #else
              typename E::const_iterator1 it1e (begin (it2e, iterator2_tag ()));
              typename E::const_iterator1 it1e_end (end (it2e, iterator2_tag ()));
  #endif
              while (it1e != it1e_end) {
                  value_type t (*it1e);
                  if (t != value_type/*zero*/())
                      m.insert_element (it1e.index1 (), it1e.index2 (), t);
                  ++ it1e;
              }
              ++ it2e;
          }
      }
      // Sparse proxy or functional row major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign (M &m, const matrix_expression<E> &e, sparse_proxy_tag, row_major_tag) {
          typedef typename matrix_traits<E>::value_type expr_value_type;
          typedef F<typename M::iterator2::reference, expr_value_type> functor_type;
          typedef R conformant_restrict_type;
          typedef typename M::size_type size_type;
          typedef typename M::difference_type difference_type;
  
          BOOST_UBLAS_CHECK (m.size1 () == e ().size1 (), bad_size ());
          BOOST_UBLAS_CHECK (m.size2 () == e ().size2 (), bad_size ());
  
  #if BOOST_UBLAS_TYPE_CHECK
          typedef typename M::value_type value_type;
          matrix<value_type, row_major> cm (m.size1 (), m.size2 ());
          indexing_matrix_assign<scalar_assign> (cm, m, row_major_tag ());
          indexing_matrix_assign<F> (cm, e, row_major_tag ());
  #endif
          detail::make_conformant (m, e, row_major_tag (), conformant_restrict_type ());
  
          typename M::iterator1 it1 (m.begin1 ());
          typename M::iterator1 it1_end (m.end1 ());
          typename E::const_iterator1 it1e (e ().begin1 ());
          typename E::const_iterator1 it1e_end (e ().end1 ());
          while (it1 != it1_end && it1e != it1e_end) {
              difference_type compare = it1.index1 () - it1e.index1 ();
              if (compare == 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename M::iterator2 it2 (it1.begin ());
                  typename M::iterator2 it2_end (it1.end ());
                  typename E::const_iterator2 it2e (it1e.begin ());
                  typename E::const_iterator2 it2e_end (it1e.end ());
  #else
                  typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
                  typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
                  typename E::const_iterator2 it2e (begin (it1e, iterator1_tag ()));
                  typename E::const_iterator2 it2e_end (end (it1e, iterator1_tag ()));
  #endif
                  if (it2 != it2_end && it2e != it2e_end) {
                      size_type it2_index = it2.index2 (), it2e_index = it2e.index2 ();
                      while (true) {
                          difference_type compare2 = it2_index - it2e_index;
                          if (compare2 == 0) {
                              functor_type::apply (*it2, *it2e);
                              ++ it2, ++ it2e;
                              if (it2 != it2_end && it2e != it2e_end) {
                                  it2_index = it2.index2 ();
                                  it2e_index = it2e.index2 ();
                              } else
                                  break;
                          } else if (compare2 < 0) {
                              if (!functor_type::computed) {
                                  functor_type::apply (*it2, expr_value_type/*zero*/());
                                  ++ it2;
                              } else
                                  increment (it2, it2_end, - compare2);
                              if (it2 != it2_end)
                                  it2_index = it2.index2 ();
                              else
                                  break;
                          } else if (compare2 > 0) {
                              increment (it2e, it2e_end, compare2);
                              if (it2e != it2e_end)
                                  it2e_index = it2e.index2 ();
                              else
                                  break;
                          }
                      }
                  }
                  if (!functor_type::computed) {
                      while (it2 != it2_end) {    // zeroing
                          functor_type::apply (*it2, expr_value_type/*zero*/());
                          ++ it2;
                      }
                  } else {
                      it2 = it2_end;
                  }
                  ++ it1, ++ it1e;
              } else if (compare < 0) {
                  if (!functor_type::computed) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                      typename M::iterator2 it2 (it1.begin ());
                      typename M::iterator2 it2_end (it1.end ());
  #else
                      typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
                      typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
  #endif
                      while (it2 != it2_end) {    // zeroing
                          functor_type::apply (*it2, expr_value_type/*zero*/());
                          ++ it2;
                      }
                      ++ it1;
                  } else {
                      increment (it1, it1_end, - compare);
                  }
              } else if (compare > 0) {
                  increment (it1e, it1e_end, compare);
              }
          }
          if (!functor_type::computed) {
              while (it1 != it1_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename M::iterator2 it2 (it1.begin ());
                  typename M::iterator2 it2_end (it1.end ());
  #else
                  typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
                  typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
  #endif
                  while (it2 != it2_end) {    // zeroing
                      functor_type::apply (*it2, expr_value_type/*zero*/());
                      ++ it2;
                  }
                  ++ it1;
              }
          } else {
              it1 = it1_end;
          }
  #if BOOST_UBLAS_TYPE_CHECK
          if (! disable_type_check<bool>::value)
              BOOST_UBLAS_CHECK (detail::expression_type_check (m, cm), external_logic ());
  #endif
      }
      // Sparse proxy or functional column major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_assign (M &m, const matrix_expression<E> &e, sparse_proxy_tag, column_major_tag) {
          typedef typename matrix_traits<E>::value_type expr_value_type;
          typedef F<typename M::iterator1::reference, expr_value_type> functor_type;
          typedef R conformant_restrict_type;
          typedef typename M::size_type size_type;
          typedef typename M::difference_type difference_type;
  
          BOOST_UBLAS_CHECK (m.size1 () == e ().size1 (), bad_size ());
          BOOST_UBLAS_CHECK (m.size2 () == e ().size2 (), bad_size ());
  
  #if BOOST_UBLAS_TYPE_CHECK
          typedef typename M::value_type value_type;
          matrix<value_type, column_major> cm (m.size1 (), m.size2 ());
          indexing_matrix_assign<scalar_assign> (cm, m, column_major_tag ());
          indexing_matrix_assign<F> (cm, e, column_major_tag ());
  #endif
          detail::make_conformant (m, e, column_major_tag (), conformant_restrict_type ());
  
          typename M::iterator2 it2 (m.begin2 ());
          typename M::iterator2 it2_end (m.end2 ());
          typename E::const_iterator2 it2e (e ().begin2 ());
          typename E::const_iterator2 it2e_end (e ().end2 ());
          while (it2 != it2_end && it2e != it2e_end) {
              difference_type compare = it2.index2 () - it2e.index2 ();
              if (compare == 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename M::iterator1 it1 (it2.begin ());
                  typename M::iterator1 it1_end (it2.end ());
                  typename E::const_iterator1 it1e (it2e.begin ());
                  typename E::const_iterator1 it1e_end (it2e.end ());
  #else
                  typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
                  typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
                  typename E::const_iterator1 it1e (begin (it2e, iterator2_tag ()));
                  typename E::const_iterator1 it1e_end (end (it2e, iterator2_tag ()));
  #endif
                  if (it1 != it1_end && it1e != it1e_end) {
                      size_type it1_index = it1.index1 (), it1e_index = it1e.index1 ();
                      while (true) {
                          difference_type compare2 = it1_index - it1e_index;
                          if (compare2 == 0) {
                              functor_type::apply (*it1, *it1e);
                              ++ it1, ++ it1e;
                              if (it1 != it1_end && it1e != it1e_end) {
                                  it1_index = it1.index1 ();
                                  it1e_index = it1e.index1 ();
                              } else
                                  break;
                          } else if (compare2 < 0) {
                              if (!functor_type::computed) {
                                  functor_type::apply (*it1, expr_value_type/*zero*/()); // zeroing
                                  ++ it1;
                              } else
                                  increment (it1, it1_end, - compare2);
                              if (it1 != it1_end)
                                  it1_index = it1.index1 ();
                              else
                                  break;
                          } else if (compare2 > 0) {
                              increment (it1e, it1e_end, compare2);
                              if (it1e != it1e_end)
                                  it1e_index = it1e.index1 ();
                              else
                                  break;
                          }
                      }
                  }
                  if (!functor_type::computed) {
                      while (it1 != it1_end) {    // zeroing
                          functor_type::apply (*it1, expr_value_type/*zero*/());
                          ++ it1;
                      }
                  } else {
                      it1 = it1_end;
                  }
                  ++ it2, ++ it2e;
              } else if (compare < 0) {
                  if (!functor_type::computed) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                      typename M::iterator1 it1 (it2.begin ());
                      typename M::iterator1 it1_end (it2.end ());
  #else
                      typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
                      typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
  #endif
                      while (it1 != it1_end) {    // zeroing
                          functor_type::apply (*it1, expr_value_type/*zero*/());
                          ++ it1;
                      }
                      ++ it2;
                  } else {
                      increment (it2, it2_end, - compare);
                  }
              } else if (compare > 0) {
                  increment (it2e, it2e_end, compare);
              }
          }
          if (!functor_type::computed) {
              while (it2 != it2_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename M::iterator1 it1 (it2.begin ());
                  typename M::iterator1 it1_end (it2.end ());
  #else
                  typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
                  typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
  #endif
                  while (it1 != it1_end) {    // zeroing
                      functor_type::apply (*it1, expr_value_type/*zero*/());
                      ++ it1;
                  }
                  ++ it2;
              }
          } else {
              it2 = it2_end;
          }
  #if BOOST_UBLAS_TYPE_CHECK
          if (! disable_type_check<bool>::value)
              BOOST_UBLAS_CHECK (detail::expression_type_check (m, cm), external_logic ());
  #endif
      }
  
      // Dispatcher
      template<template <class T1, class T2> class F, class M, class E>
      BOOST_UBLAS_INLINE
      void matrix_assign (M &m, const matrix_expression<E> &e) {
          typedef typename matrix_assign_traits<typename M::storage_category,
                                                F<typename M::reference, typename E::value_type>::computed,
                                                typename E::const_iterator1::iterator_category,
                                                typename E::const_iterator2::iterator_category>::storage_category storage_category;
          // give preference to matrix M's orientation if known
          typedef typename boost::mpl::if_<boost::is_same<typename M::orientation_category, unknown_orientation_tag>,
                                            typename E::orientation_category ,
                                            typename M::orientation_category >::type orientation_category;
          typedef basic_full<typename M::size_type> unrestricted;
          matrix_assign<F, unrestricted> (m, e, storage_category (), orientation_category ());
      }
      template<template <class T1, class T2> class F, class R, class M, class E>
      BOOST_UBLAS_INLINE
      void matrix_assign (M &m, const matrix_expression<E> &e) {
          typedef R conformant_restrict_type;
          typedef typename matrix_assign_traits<typename M::storage_category,
                                                F<typename M::reference, typename E::value_type>::computed,
                                                typename E::const_iterator1::iterator_category,
                                                typename E::const_iterator2::iterator_category>::storage_category storage_category;
          // give preference to matrix M's orientation if known
          typedef typename boost::mpl::if_<boost::is_same<typename M::orientation_category, unknown_orientation_tag>,
                                            typename E::orientation_category ,
                                            typename M::orientation_category >::type orientation_category;
          matrix_assign<F, conformant_restrict_type> (m, e, storage_category (), orientation_category ());
      }
  
      template<class SC, class RI1, class RI2>
      struct matrix_swap_traits {
          typedef SC storage_category;
      };
  
      template<>
      struct matrix_swap_traits<dense_proxy_tag, sparse_bidirectional_iterator_tag, sparse_bidirectional_iterator_tag> {
          typedef sparse_proxy_tag storage_category;
      };
  
      template<>
      struct matrix_swap_traits<packed_proxy_tag, sparse_bidirectional_iterator_tag, sparse_bidirectional_iterator_tag> {
          typedef sparse_proxy_tag storage_category;
      };
  
      // Dense (proxy) row major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_swap (M &m, matrix_expression<E> &e, dense_proxy_tag, row_major_tag) {
          typedef F<typename M::iterator2::reference, typename E::reference> functor_type;
          // R unnecessary, make_conformant not required
          //typedef typename M::size_type size_type; // gcc is complaining that this is not used, although this is not right
          typedef typename M::difference_type difference_type;
          typename M::iterator1 it1 (m.begin1 ());
          typename E::iterator1 it1e (e ().begin1 ());
          difference_type size1 (BOOST_UBLAS_SAME (m.size1 (), typename M::size_type (e ().end1 () - it1e)));
          while (-- size1 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator2 it2 (it1.begin ());
              typename E::iterator2 it2e (it1e.begin ());
              difference_type size2 (BOOST_UBLAS_SAME (m.size2 (), typename M::size_type (it1e.end () - it2e)));
  #else
              typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
              typename E::iterator2 it2e (begin (it1e, iterator1_tag ()));
              difference_type size2 (BOOST_UBLAS_SAME (m.size2 (), typename M::size_type (end (it1e, iterator1_tag ()) - it2e)));
  #endif
              while (-- size2 >= 0)
                  functor_type::apply (*it2, *it2e), ++ it2, ++ it2e;
              ++ it1, ++ it1e;
          }
      }
      // Dense (proxy) column major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_swap (M &m, matrix_expression<E> &e, dense_proxy_tag, column_major_tag) {
          typedef F<typename M::iterator1::reference, typename E::reference> functor_type;
          // R unnecessary, make_conformant not required
          // typedef typename M::size_type size_type; // gcc is complaining that this is not used, although this is not right
          typedef typename M::difference_type difference_type;
          typename M::iterator2 it2 (m.begin2 ());
          typename E::iterator2 it2e (e ().begin2 ());
          difference_type size2 (BOOST_UBLAS_SAME (m.size2 (), typename M::size_type (e ().end2 () - it2e)));
          while (-- size2 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator1 it1 (it2.begin ());
              typename E::iterator1 it1e (it2e.begin ());
              difference_type size1 (BOOST_UBLAS_SAME (m.size1 (), typename M::size_type (it2e.end () - it1e)));
  #else
              typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
              typename E::iterator1 it1e (begin (it2e, iterator2_tag ()));
              difference_type size1 (BOOST_UBLAS_SAME (m.size1 (), typename M::size_type (end (it2e, iterator2_tag ()) - it1e)));
  #endif
              while (-- size1 >= 0)
                  functor_type::apply (*it1, *it1e), ++ it1, ++ it1e;
              ++ it2, ++ it2e;
          }
      }
      // Packed (proxy) row major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_swap (M &m, matrix_expression<E> &e, packed_proxy_tag, row_major_tag) {
          typedef F<typename M::iterator2::reference, typename E::reference> functor_type;
          // R unnecessary, make_conformant not required
          typedef typename M::difference_type difference_type;
          typename M::iterator1 it1 (m.begin1 ());
          typename E::iterator1 it1e (e ().begin1 ());
          difference_type size1 (BOOST_UBLAS_SAME (m.end1 () - it1, e ().end1 () - it1e));
          while (-- size1 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator2 it2 (it1.begin ());
              typename E::iterator2 it2e (it1e.begin ());
              difference_type size2 (BOOST_UBLAS_SAME (it1.end () - it2, it1e.end () - it2e));
  #else
              typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
              typename E::iterator2 it2e (begin (it1e, iterator1_tag ()));
              difference_type size2 (BOOST_UBLAS_SAME (end (it1, iterator1_tag ()) - it2, end (it1e, iterator1_tag ()) - it2e));
  #endif
              while (-- size2 >= 0)
                  functor_type::apply (*it2, *it2e), ++ it2, ++ it2e;
              ++ it1, ++ it1e;
          }
      }
      // Packed (proxy) column major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_swap (M &m, matrix_expression<E> &e, packed_proxy_tag, column_major_tag) {
          typedef F<typename M::iterator1::reference, typename E::reference> functor_type;
          // R unnecessary, make_conformant not required
          typedef typename M::difference_type difference_type;
          typename M::iterator2 it2 (m.begin2 ());
          typename E::iterator2 it2e (e ().begin2 ());
          difference_type size2 (BOOST_UBLAS_SAME (m.end2 () - it2, e ().end2 () - it2e));
          while (-- size2 >= 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator1 it1 (it2.begin ());
              typename E::iterator1 it1e (it2e.begin ());
              difference_type size1 (BOOST_UBLAS_SAME (it2.end () - it1, it2e.end () - it1e));
  #else
              typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
              typename E::iterator1 it1e (begin (it2e, iterator2_tag ()));
              difference_type size1 (BOOST_UBLAS_SAME (end (it2, iterator2_tag ()) - it1, end (it2e, iterator2_tag ()) - it1e));
  #endif
              while (-- size1 >= 0)
                  functor_type::apply (*it1, *it1e), ++ it1, ++ it1e;
              ++ it2, ++ it2e;
          }
      }
      // Sparse (proxy) row major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_swap (M &m, matrix_expression<E> &e, sparse_proxy_tag, row_major_tag) {
          typedef F<typename M::iterator2::reference, typename E::reference> functor_type;
          typedef R conformant_restrict_type;
          typedef typename M::size_type size_type;
          typedef typename M::difference_type difference_type;
          BOOST_UBLAS_CHECK (m.size1 () == e ().size1 (), bad_size ());
          BOOST_UBLAS_CHECK (m.size2 () == e ().size2 (), bad_size ());
  
          detail::make_conformant (m, e, row_major_tag (), conformant_restrict_type ());
          // FIXME should be a seperate restriction for E
          detail::make_conformant (e (), m, row_major_tag (), conformant_restrict_type ());
  
          typename M::iterator1 it1 (m.begin1 ());
          typename M::iterator1 it1_end (m.end1 ());
          typename E::iterator1 it1e (e ().begin1 ());
          typename E::iterator1 it1e_end (e ().end1 ());
          while (it1 != it1_end && it1e != it1e_end) {
              difference_type compare = it1.index1 () - it1e.index1 ();
              if (compare == 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename M::iterator2 it2 (it1.begin ());
                  typename M::iterator2 it2_end (it1.end ());
                  typename E::iterator2 it2e (it1e.begin ());
                  typename E::iterator2 it2e_end (it1e.end ());
  #else
                  typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
                  typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
                  typename E::iterator2 it2e (begin (it1e, iterator1_tag ()));
                  typename E::iterator2 it2e_end (end (it1e, iterator1_tag ()));
  #endif
                  if (it2 != it2_end && it2e != it2e_end) {
                      size_type it2_index = it2.index2 (), it2e_index = it2e.index2 ();
                      while (true) {
                          difference_type compare2 = it2_index - it2e_index;
                          if (compare2 == 0) {
                              functor_type::apply (*it2, *it2e);
                              ++ it2, ++ it2e;
                              if (it2 != it2_end && it2e != it2e_end) {
                                  it2_index = it2.index2 ();
                                  it2e_index = it2e.index2 ();
                              } else
                                  break;
                          } else if (compare2 < 0) {
                              increment (it2, it2_end, - compare2);
                              if (it2 != it2_end)
                                  it2_index = it2.index2 ();
                              else
                                  break;
                          } else if (compare2 > 0) {
                              increment (it2e, it2e_end, compare2);
                              if (it2e != it2e_end)
                                  it2e_index = it2e.index2 ();
                              else
                                  break;
                          }
                      }
                  }
  #if BOOST_UBLAS_TYPE_CHECK
                  increment (it2e, it2e_end);
                  increment (it2, it2_end);
  #endif
                  ++ it1, ++ it1e;
              } else if (compare < 0) {
  #if BOOST_UBLAS_TYPE_CHECK
                  while (it1.index1 () < it1e.index1 ()) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                      typename M::iterator2 it2 (it1.begin ());
                      typename M::iterator2 it2_end (it1.end ());
  #else
                      typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
                      typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
  #endif
                      increment (it2, it2_end);
                      ++ it1;
                  }
  #else
                  increment (it1, it1_end, - compare);
  #endif
              } else if (compare > 0) {
  #if BOOST_UBLAS_TYPE_CHECK
                  while (it1e.index1 () < it1.index1 ()) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                      typename E::iterator2 it2e (it1e.begin ());
                      typename E::iterator2 it2e_end (it1e.end ());
  #else
                      typename E::iterator2 it2e (begin (it1e, iterator1_tag ()));
                      typename E::iterator2 it2e_end (end (it1e, iterator1_tag ()));
  #endif
                      increment (it2e, it2e_end);
                      ++ it1e;
                  }
  #else
                  increment (it1e, it1e_end, compare);
  #endif
              }
          }
  #if BOOST_UBLAS_TYPE_CHECK
          while (it1e != it1e_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename E::iterator2 it2e (it1e.begin ());
              typename E::iterator2 it2e_end (it1e.end ());
  #else
              typename E::iterator2 it2e (begin (it1e, iterator1_tag ()));
              typename E::iterator2 it2e_end (end (it1e, iterator1_tag ()));
  #endif
              increment (it2e, it2e_end);
              ++ it1e;
          }
          while (it1 != it1_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator2 it2 (it1.begin ());
              typename M::iterator2 it2_end (it1.end ());
  #else
              typename M::iterator2 it2 (begin (it1, iterator1_tag ()));
              typename M::iterator2 it2_end (end (it1, iterator1_tag ()));
  #endif
              increment (it2, it2_end);
              ++ it1;
          }
  #endif
      }
      // Sparse (proxy) column major case
      template<template <class T1, class T2> class F, class R, class M, class E>
      // BOOST_UBLAS_INLINE This function seems to be big. So we do not let the compiler inline it.
      void matrix_swap (M &m, matrix_expression<E> &e, sparse_proxy_tag, column_major_tag) {
          typedef F<typename M::iterator1::reference, typename E::reference> functor_type;
          typedef R conformant_restrict_type;
          typedef typename M::size_type size_type;
          typedef typename M::difference_type difference_type;
  
          BOOST_UBLAS_CHECK (m.size1 () == e ().size1 (), bad_size ());
          BOOST_UBLAS_CHECK (m.size2 () == e ().size2 (), bad_size ());
  
          detail::make_conformant (m, e, column_major_tag (), conformant_restrict_type ());
          // FIXME should be a seperate restriction for E
          detail::make_conformant (e (), m, column_major_tag (), conformant_restrict_type ());
  
          typename M::iterator2 it2 (m.begin2 ());
          typename M::iterator2 it2_end (m.end2 ());
          typename E::iterator2 it2e (e ().begin2 ());
          typename E::iterator2 it2e_end (e ().end2 ());
          while (it2 != it2_end && it2e != it2e_end) {
              difference_type compare = it2.index2 () - it2e.index2 ();
              if (compare == 0) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                  typename M::iterator1 it1 (it2.begin ());
                  typename M::iterator1 it1_end (it2.end ());
                  typename E::iterator1 it1e (it2e.begin ());
                  typename E::iterator1 it1e_end (it2e.end ());
  #else
                  typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
                  typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
                  typename E::iterator1 it1e (begin (it2e, iterator2_tag ()));
                  typename E::iterator1 it1e_end (end (it2e, iterator2_tag ()));
  #endif
                  if (it1 != it1_end && it1e != it1e_end) {
                      size_type it1_index = it1.index1 (), it1e_index = it1e.index1 ();
                      while (true) {
                          difference_type compare2 = it1_index - it1e_index;
                          if (compare2 == 0) {
                              functor_type::apply (*it1, *it1e);
                              ++ it1, ++ it1e;
                              if (it1 != it1_end && it1e != it1e_end) {
                                  it1_index = it1.index1 ();
                                  it1e_index = it1e.index1 ();
                              } else
                                  break;
                          }  else if (compare2 < 0) {
                              increment (it1, it1_end, - compare2);
                              if (it1 != it1_end)
                                  it1_index = it1.index1 ();
                              else
                                  break;
                          } else if (compare2 > 0) {
                              increment (it1e, it1e_end, compare2);
                              if (it1e != it1e_end)
                                  it1e_index = it1e.index1 ();
                              else
                                  break;
                          }
                      }
                  }
  #if BOOST_UBLAS_TYPE_CHECK
                  increment (it1e, it1e_end);
                  increment (it1, it1_end);
  #endif
                  ++ it2, ++ it2e;
              } else if (compare < 0) {
  #if BOOST_UBLAS_TYPE_CHECK
                  while (it2.index2 () < it2e.index2 ()) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                      typename M::iterator1 it1 (it2.begin ());
                      typename M::iterator1 it1_end (it2.end ());
  #else
                      typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
                      typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
  #endif
                      increment (it1, it1_end);
                      ++ it2;
                  }
  #else
                  increment (it2, it2_end, - compare);
  #endif
              } else if (compare > 0) {
  #if BOOST_UBLAS_TYPE_CHECK
                  while (it2e.index2 () < it2.index2 ()) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
                      typename E::iterator1 it1e (it2e.begin ());
                      typename E::iterator1 it1e_end (it2e.end ());
  #else
                      typename E::iterator1 it1e (begin (it2e, iterator2_tag ()));
                      typename E::iterator1 it1e_end (end (it2e, iterator2_tag ()));
  #endif
                      increment (it1e, it1e_end);
                      ++ it2e;
                  }
  #else
                  increment (it2e, it2e_end, compare);
  #endif
              }
          }
  #if BOOST_UBLAS_TYPE_CHECK
          while (it2e != it2e_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename E::iterator1 it1e (it2e.begin ());
              typename E::iterator1 it1e_end (it2e.end ());
  #else
              typename E::iterator1 it1e (begin (it2e, iterator2_tag ()));
              typename E::iterator1 it1e_end (end (it2e, iterator2_tag ()));
  #endif
              increment (it1e, it1e_end);
              ++ it2e;
          }
          while (it2 != it2_end) {
  #ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
              typename M::iterator1 it1 (it2.begin ());
              typename M::iterator1 it1_end (it2.end ());
  #else
              typename M::iterator1 it1 (begin (it2, iterator2_tag ()));
              typename M::iterator1 it1_end (end (it2, iterator2_tag ()));
  #endif
              increment (it1, it1_end);
              ++ it2;
          }
  #endif
      }
  
      // Dispatcher
      template<template <class T1, class T2> class F, class M, class E>
      BOOST_UBLAS_INLINE
      void matrix_swap (M &m, matrix_expression<E> &e) {
          typedef typename matrix_swap_traits<typename M::storage_category,
                                              typename E::const_iterator1::iterator_category,
                                              typename E::const_iterator2::iterator_category>::storage_category storage_category;
          // give preference to matrix M's orientation if known
          typedef typename boost::mpl::if_<boost::is_same<typename M::orientation_category, unknown_orientation_tag>,
                                            typename E::orientation_category ,
                                            typename M::orientation_category >::type orientation_category;
          typedef basic_full<typename M::size_type> unrestricted;
          matrix_swap<F, unrestricted> (m, e, storage_category (), orientation_category ());
      }
      template<template <class T1, class T2> class F, class R, class M, class E>
      BOOST_UBLAS_INLINE
      void matrix_swap (M &m, matrix_expression<E> &e) {
          typedef R conformant_restrict_type;
          typedef typename matrix_swap_traits<typename M::storage_category,
                                              typename E::const_iterator1::iterator_category,
                                              typename E::const_iterator2::iterator_category>::storage_category storage_category;
          // give preference to matrix M's orientation if known
          typedef typename boost::mpl::if_<boost::is_same<typename M::orientation_category, unknown_orientation_tag>,
                                            typename E::orientation_category ,
                                            typename M::orientation_category >::type orientation_category;
          matrix_swap<F, conformant_restrict_type> (m, e, storage_category (), orientation_category ());
      }
  
  }}}
  
  #endif
  