eina-cxx: Added range_list to range types for eina-cxx

Added range_list which abstracts a ptr_list for wrapper types.

diff --git a/src/bindings/eina_cxx/eina_list.hh b/src/bindings/eina_cxx/eina_list.hh
index dbdfea9..ec54f42 100644 (file)
--- a/src/bindings/eina_cxx/eina_list.hh
+++ b/src/bindings/eina_cxx/eina_list.hh
@@ -73,6 +73,100 @@ struct _ptr_eo_list_iterator : _ptr_list_iterator<Eo>
   using _base_type::native_handle;
 };
 
+/**
+ * @internal
+ */
+struct _eo_list_access_traits : _ptr_list_access_traits
+{
+  template <typename T>
+  struct iterator
+  {
+    typedef _ptr_eo_list_iterator<T> type;
+  };
+  template <typename T>
+  struct const_iterator : iterator<T const> {};
+  template <typename T>
+  static T& back(Eina_List* list)
+  {
+    return *static_cast<T*>(static_cast<void*>(&eina_list_last(list)->data));
+  }
+  template <typename T>
+  static T const& back(Eina_List const* list)
+  {
+    return _eo_list_access_traits::back<T>(const_cast<Eina_List*>(list));
+  }
+  template <typename T>
+  static T& front(Eina_List* list)
+  {
+    return *static_cast<T*>(static_cast<void*>(&list->data));
+  }
+  template <typename T>
+  static T const& front(Eina_List const* list)
+  {
+    return _eo_list_access_traits::front<T>(const_cast<Eina_List*>(list));
+  }
+  template <typename T>
+  static typename iterator<T>::type begin(Eina_List* list)
+  {
+    return typename iterator<T>::type(list, list);
+  }
+  template <typename T>
+  static typename iterator<T>::type end(Eina_List* list)
+  {
+    return typename iterator<T>::type(list, nullptr);
+  }
+  template <typename T>
+  static typename const_iterator<T>::type begin(Eina_List const* list)
+  {
+    return _eo_list_access_traits::begin<T>(const_cast<Eina_List*>(list));
+  }
+  template <typename T>
+  static typename const_iterator<T>::type end(Eina_List const* list)
+  {
+    return _eo_list_access_traits::end<T>(const_cast<Eina_List*>(list));
+  }
+  template <typename T>
+  static std::reverse_iterator<typename iterator<T>::type> rbegin(Eina_List* list)
+  {
+    return std::reverse_iterator<typename iterator<T>::type>(_eo_list_access_traits::end<T>(list));
+  }
+  template <typename T>
+  static std::reverse_iterator<typename iterator<T>::type> rend(Eina_List* list)
+  {
+    return std::reverse_iterator<typename iterator<T>::type>(_eo_list_access_traits::begin<T>(list));
+  }
+  template <typename T>
+  static std::reverse_iterator<typename const_iterator<T>::type> rbegin(Eina_List const* list)
+  {
+    return _eo_list_access_traits::rbegin<T>(const_cast<Eina_List*>(list));
+  }
+  template <typename T>
+  static std::reverse_iterator<typename const_iterator<T>::type> rend(Eina_List const* list)
+  {
+    return _eo_list_access_traits::rend<T>(const_cast<Eina_List*>(list));
+  }
+  template <typename T>
+  static typename const_iterator<T>::type cbegin(Eina_List const* list)
+  {
+    return _eo_list_access_traits::begin<T>(list);
+  }
+  template <typename T>
+  static typename const_iterator<T>::type cend(Eina_List const* list)
+  {
+    return _eo_list_access_traits::end<T>(list);
+  }
+  template <typename T>
+  static std::reverse_iterator<typename const_iterator<T>::type> crbegin(Eina_List const* list)
+  {
+    return _eo_list_access_traits::rbegin<T>(list);
+  }
+  template <typename T>
+  static std::reverse_iterator<typename const_iterator<T>::type> crend(Eina_List const* list)
+  {
+    return _eo_list_access_traits::rend<T>(list);
+  }
+};
+    
 template <typename T, typename CloneAllocator = default_clone_allocator_placeholder, typename Enable = void>
 class list : ptr_list<T, typename std::conditional
                       <std::is_same<CloneAllocator, default_clone_allocator_placeholder>::value
@@ -253,21 +347,21 @@ public:
   
   reference front()
   {
-    return *static_cast<pointer>(static_cast<void*>(&native_handle()->data));
+    return _eo_list_access_traits::front<value_type>(native_handle());
   }
   reference back()
   {
-    return *static_cast<pointer>(static_cast<void*>(&eina_list_last(native_handle())->data));
+    return _eo_list_access_traits::back<value_type>(native_handle());
   }
   const_reference front() const { return const_cast<_self_type*>(this)->front(); }
   const_reference back() const { return const_cast<_self_type*>(this)->back(); }
   iterator begin()
   {
-    return iterator(native_handle(), native_handle());
+    return _eo_list_access_traits::begin<value_type>(native_handle());
   }
   iterator end()
   {
-    return iterator(native_handle(), nullptr);
+    return _eo_list_access_traits::end<value_type>(native_handle());
   }
   const_iterator begin() const
   {
@@ -287,11 +381,11 @@ public:
   }
   reverse_iterator rbegin()
   {
-    return reverse_iterator(end());
+    return _eo_list_access_traits::rbegin<value_type>(native_handle());
   }
   reverse_iterator rend()
   {
-    return reverse_iterator(begin());
+    return _eo_list_access_traits::rend<value_type>(native_handle());
   }
   const_reverse_iterator rbegin() const
   {
@@ -324,6 +418,160 @@ bool operator!=(list<T, CloneAllocator> const& rhs, list<T, CloneAllocator> cons
 {
   return !(rhs == lhs);
 }
+
+template <typename T, typename Enable = void>
+class range_list : range_ptr_list<T>
+{
+  typedef range_ptr_list<T> _base_type;
+public:
+  typedef typename _base_type::value_type value_type;
+  typedef typename _base_type::reference reference;
+  typedef typename _base_type::const_reference const_reference;
+  typedef typename _base_type::const_iterator const_iterator;
+  typedef typename _base_type::iterator iterator;
+  typedef typename _base_type::pointer pointer;
+  typedef typename _base_type::const_pointer const_pointer;
+  typedef typename _base_type::size_type size_type;
+  typedef typename _base_type::difference_type difference_type;
+  typedef typename _base_type::clone_allocator_type clone_allocator_type;
+
+  typedef typename _base_type::reverse_iterator reverse_iterator;
+  typedef typename _base_type::const_reverse_iterator const_reverse_iterator;
+
+  using _base_type::_base_type;
+  using _base_type::clear;
+  using _base_type::size;
+  using _base_type::empty;
+  using _base_type::get_clone_allocator;
+  using _base_type::push_back;
+  using _base_type::push_front;
+  using _base_type::pop_back;
+  using _base_type::pop_front;
+  using _base_type::insert;
+  using _base_type::erase;
+  using _base_type::assign;
+  using _base_type::back;
+  using _base_type::front;
+  using _base_type::begin;
+  using _base_type::end;
+  using _base_type::rbegin;
+  using _base_type::rend;
+  using _base_type::cbegin;
+  using _base_type::cend;
+  using _base_type::crbegin;
+  using _base_type::crend;
+  using _base_type::ibegin;
+  using _base_type::iend;
+  using _base_type::cibegin;
+  using _base_type::ciend;
+  using _base_type::swap;
+  using _base_type::max_size;
+  using _base_type::native_handle;
+  using _base_type::accessor;
+};
+
+template <typename T>
+class range_list<T, typename std::enable_if<std::is_base_of<efl::eo::base, T>::value>::type>
+  : range_ptr_list<Eo>
+{
+  typedef range_ptr_list<Eo> _base_type;
+  typedef range_list<T> _self_type;
+public:
+  typedef T value_type;
+  typedef value_type& reference;
+  typedef value_type const& const_reference;
+  typedef _ptr_eo_list_iterator<value_type const> const_iterator;
+  typedef _ptr_eo_list_iterator<value_type> iterator;
+  typedef value_type* pointer;
+  typedef value_type const* const_pointer;
+  typedef std::size_t size_type;
+  typedef std::ptrdiff_t difference_type;
+
+  typedef std::reverse_iterator<iterator> reverse_iterator;
+  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
+
+  explicit range_list(Eina_List* handle)
+    : _base_type(handle) {}
+  range_list() {}
+  range_list(range_list<T> const& other)
+    : _base_type(other.native_handle())
+  {
+  }
+  range_list<T>& operator=(range_list<T>const& other)
+  {
+    _base_type::_handle = other._handle;
+    return *this;
+  }
+  
+  using _base_type::size;
+  using _base_type::empty;
+
+  reference front()
+  {
+    return _eo_list_access_traits::front<value_type>(native_handle());
+  }
+  reference back()
+  {
+    return _eo_list_access_traits::back<value_type>(native_handle());
+  }
+  const_reference front() const { return const_cast<_self_type*>(this)->front(); }
+  const_reference back() const { return const_cast<_self_type*>(this)->back(); }
+  iterator begin()
+  {
+    return _eo_list_access_traits::begin<value_type>(native_handle());
+  }
+  iterator end()
+  {
+    return _eo_list_access_traits::end<value_type>(native_handle());
+  }
+  const_iterator begin() const
+  {
+    return const_cast<_self_type*>(this)->begin();
+  }
+  const_iterator end() const
+  {
+    return const_cast<_self_type*>(this)->end();
+  }
+  const_iterator cbegin() const
+  {
+    return begin();
+  }
+  const_iterator cend() const
+  {
+    return end();
+  }
+  reverse_iterator rbegin()
+  {
+    return _eo_list_access_traits::rbegin<value_type>(native_handle());
+  }
+  reverse_iterator rend()
+  {
+    return _eo_list_access_traits::rend<value_type>(native_handle());
+  }
+  const_reverse_iterator rbegin() const
+  {
+    return const_cast<_self_type*>(this)->rbegin();
+  }
+  const_reverse_iterator rend() const
+  {
+    return const_cast<_self_type*>(this)->rend();
+  }
+  const_reverse_iterator crbegin() const
+  {
+    return rbegin();
+  }
+  const_reverse_iterator crend() const
+  {
+    return rend();
+  }
+  using _base_type::swap;
+  using _base_type::native_handle;
+
+  friend bool operator==(range_list<T> const& rhs, range_list<T> const& lhs)
+  {
+    return rhs.size() == lhs.size() && std::equal(rhs.begin(), rhs.end(), lhs.begin());
+  }
+};
     
 } }
 

diff --git a/src/bindings/eina_cxx/eina_ptrlist.hh b/src/bindings/eina_cxx/eina_ptrlist.hh
index 1cddce0..140c5ce 100644 (file)
--- a/src/bindings/eina_cxx/eina_ptrlist.hh
+++ b/src/bindings/eina_cxx/eina_ptrlist.hh
@@ -120,295 +120,149 @@ struct _ptr_list_iterator : _ptr_list_iterator_base
 /**
  * @internal
  */
-struct _ptr_list_access_traits {
-
-template <typename T>
-struct iterator
-{
-  typedef _ptr_list_iterator<T> type;
-};
-template <typename T>
-struct const_iterator : iterator<T const> {};
-template <typename T>
-struct native_handle
-{
-  typedef Eina_List* type;
-};
-template <typename T>
-struct const_native_handle
-{
-  typedef Eina_List const* type;
-};
-template <typename T>
-static Eina_List* native_handle_from_const(Eina_List const* list)
-{
-  return const_cast<Eina_List*>(list);
-}
-template <typename T>
-static T& back(Eina_List* list)
-{
-  return *static_cast<T*>(eina_list_data_get(eina_list_last(list)));
-}
-template <typename T>
-static T const& back(Eina_List const* list)
-{
-  return _ptr_list_access_traits::back<T>(const_cast<Eina_List*>(list));
-}
-template <typename T>
-static T& front(Eina_List* list)
-{
-  return *static_cast<T*>(eina_list_data_get(list));
-}
-template <typename T>
-static T const& front(Eina_List const* list)
-{
-  return _ptr_list_access_traits::front<T>(const_cast<Eina_List*>(list));
-}
-template <typename T>
-static _ptr_list_iterator<T> begin(Eina_List* list)
-{
-  return _ptr_list_iterator<T>(list, list);
-}
-template <typename T>
-static _ptr_list_iterator<T> end(Eina_List* list)
-{
-  return _ptr_list_iterator<T>(list, 0);
-}
-template <typename T>
-static _ptr_list_iterator<T const> begin(Eina_List const* list)
-{
-  return _ptr_list_access_traits::begin<T>(const_cast<Eina_List*>(list));
-}
-template <typename T>
-static _ptr_list_iterator<T const> end(Eina_List const* list)
-{
-  return _ptr_list_access_traits::end<T>(const_cast<Eina_List*>(list));
-}
-template <typename T>
-static std::reverse_iterator<_ptr_list_iterator<T> > rbegin(Eina_List* list)
-{
-  return std::reverse_iterator<_ptr_list_iterator<T> >(_ptr_list_access_traits::end<T>(list));
-}
-template <typename T>
-static std::reverse_iterator<_ptr_list_iterator<T> > rend(Eina_List* list)
-{
-  return std::reverse_iterator<_ptr_list_iterator<T> >(_ptr_list_access_traits::begin<T>(list));
-}
-template <typename T>
-static std::reverse_iterator<_ptr_list_iterator<T const> > rbegin(Eina_List const* list)
-{
-  return _ptr_list_access_traits::rbegin<T>(const_cast<Eina_List*>(list));
-}
-template <typename T>
-static std::reverse_iterator<_ptr_list_iterator<T const> > rend(Eina_List const* list)
-{
-  return _ptr_list_access_traits::rend<T>(const_cast<Eina_List*>(list));
-}
-template <typename T>
-static _ptr_list_iterator<T const> cbegin(Eina_List const* list)
-{
-  return _ptr_list_access_traits::begin<T>(list);
-}
-template <typename T>
-static _ptr_list_iterator<T const> cend(Eina_List const* list)
-{
-  return _ptr_list_access_traits::end<T>(list);
-}
-template <typename T>
-static std::reverse_iterator<_ptr_list_iterator<T const> > crbegin(Eina_List const* list)
-{
-  return _ptr_list_access_traits::rbegin<T>(list);
-}
-template <typename T>
-static std::reverse_iterator<_ptr_list_iterator<T const> > crend(Eina_List const* list)
-{
-  return _ptr_list_access_traits::rend<T>(list);
-}
-template <typename T>
-static eina::iterator<T> ibegin(Eina_List* list)
-{
-  return eina::iterator<T>( ::eina_list_iterator_new(list) );
-}
-template <typename T>
-static eina::iterator<T> iend(Eina_List*)
-{
-  return eina::iterator<T>();
-}
-template <typename T>
-static eina::iterator<T const> ibegin(Eina_List const* list)
-{
-  return eina::iterator<T const>( ::eina_list_iterator_new(list) );
-}
-template <typename T>
-static eina::iterator<T const> iend(Eina_List const*)
+struct _ptr_list_access_traits
 {
-  return eina::iterator<T const>();
-}
-template <typename T>
-static eina::iterator<T const> cibegin(Eina_List const* list)
-{
-  return _ptr_list_access_traits::ibegin<T>(list);
-}
-template <typename T>
-static eina::iterator<T const> ciend(Eina_List const* list)
-{
-  return _ptr_list_access_traits::iend<T>(list);
-}
-template <typename T>
-static std::size_t size(Eina_List const* list)
-{
-  return eina_list_count(list);
-}
-template <typename T>
-static bool empty(Eina_List const* list)
-{
-  return _ptr_list_access_traits::size<T>(list) == 0u;
-}
-
-};
-
-/**
- * @internal
- */
-template <typename T>
-struct _const_range_ptr_list
-{
-  typedef _ptr_list_iterator<T const> const_iterator;
-  typedef const_iterator iterator;
-  typedef T value_type;
-  typedef T& reference;
-  typedef T const& const_reference;
-  typedef T* pointer;
-  typedef T const* const_pointer;
-  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
-  typedef const_reverse_iterator reverse_iterator;
-  typedef std::size_t size_type;
-  typedef std::ptrdiff_t difference_type;
-
-  typedef Eina_List const* native_handle_type;
-  typedef _const_range_ptr_list<T> _self_type;
-
-  _const_range_ptr_list(native_handle_type list)
-    : _list(list) {}
-
-  native_handle_type native_handle() const { return _list; }
-  value_type const& back() const
+  template <typename T>
+  struct iterator
+  {
+    typedef _ptr_list_iterator<T> type;
+  };
+  template <typename T>
+  struct const_iterator : iterator<T const> {};
+  template <typename T>
+  struct native_handle
+  {
+    typedef Eina_List* type;
+  };
+  template <typename T>
+  struct const_native_handle
+  {
+    typedef Eina_List const* type;
+  };
+  template <typename T>
+  static Eina_List* native_handle_from_const(Eina_List const* list)
   {
-    return _ptr_list_access_traits::back<value_type>(_list);
+    return const_cast<Eina_List*>(list);
   }
-  value_type const& front() const
+  template <typename T>
+  static T& back(Eina_List* list)
   {
-    return _ptr_list_access_traits::front<value_type>(_list);
+    return *static_cast<T*>(eina_list_data_get(eina_list_last(list)));
   }
-  const_iterator begin() const
+  template <typename T>
+  static T const& back(Eina_List const* list)
   {
-    return _ptr_list_access_traits::begin<value_type>(_list);
+    return _ptr_list_access_traits::back<T>(const_cast<Eina_List*>(list));
   }
-  const_iterator end() const
+  template <typename T>
+  static T& front(Eina_List* list)
   {
-    return _ptr_list_access_traits::end<value_type>(_list);
+    return *static_cast<T*>(eina_list_data_get(list));
   }
-  const_reverse_iterator rbegin() const
+  template <typename T>
+  static T const& front(Eina_List const* list)
   {
-    return _ptr_list_access_traits::rbegin<value_type>(_list);
+    return _ptr_list_access_traits::front<T>(const_cast<Eina_List*>(list));
   }
-  const_reverse_iterator rend() const
+  template <typename T>
+  static _ptr_list_iterator<T> begin(Eina_List* list)
   {
-    return _ptr_list_access_traits::rend<value_type>(_list);
+    return _ptr_list_iterator<T>(list, list);
   }
-  const_iterator cbegin() const
+  template <typename T>
+  static _ptr_list_iterator<T> end(Eina_List* list)
   {
-    return _ptr_list_access_traits::cbegin<value_type>(_list);
+    return _ptr_list_iterator<T>(list, 0);
   }
-  const_iterator cend() const
+  template <typename T>
+  static _ptr_list_iterator<T const> begin(Eina_List const* list)
   {
-    return _ptr_list_access_traits::cend<value_type>(_list);
+    return _ptr_list_access_traits::begin<T>(const_cast<Eina_List*>(list));
   }
-  const_reverse_iterator crbegin() const
+  template <typename T>
+  static _ptr_list_iterator<T const> end(Eina_List const* list)
   {
-    return _ptr_list_access_traits::crbegin<value_type>(_list);
+    return _ptr_list_access_traits::end<T>(const_cast<Eina_List*>(list));
   }
-  const_reverse_iterator crend() const
+  template <typename T>
+  static std::reverse_iterator<_ptr_list_iterator<T> > rbegin(Eina_List* list)
   {
-    return _ptr_list_access_traits::crend<value_type>(_list);
+    return std::reverse_iterator<_ptr_list_iterator<T> >(_ptr_list_access_traits::end<T>(list));
   }
-  void swap(_self_type& other)
+  template <typename T>
+  static std::reverse_iterator<_ptr_list_iterator<T> > rend(Eina_List* list)
   {
-    std::swap(_list, other._list);
+    return std::reverse_iterator<_ptr_list_iterator<T> >(_ptr_list_access_traits::begin<T>(list));
   }
-  bool empty() const
+  template <typename T>
+  static std::reverse_iterator<_ptr_list_iterator<T const> > rbegin(Eina_List const* list)
   {
-    return _ptr_list_access_traits::empty<T>(_list);
+    return _ptr_list_access_traits::rbegin<T>(const_cast<Eina_List*>(list));
   }
-  size_type size() const
+  template <typename T>
+  static std::reverse_iterator<_ptr_list_iterator<T const> > rend(Eina_List const* list)
   {
-    return _ptr_list_access_traits::size<T>(_list);
+    return _ptr_list_access_traits::rend<T>(const_cast<Eina_List*>(list));
   }
-
-  native_handle_type _list;
-};
-
-/**
- * @internal
- */
-template <typename T>
-void swap(_const_range_ptr_list<T>& lhs, _const_range_ptr_list<T>& rhs)
-{
-  lhs.swap(rhs);
-}
-
-/**
- * @internal
- */
-template <typename T>
-struct _mutable_range_ptr_list : _const_range_ptr_list<T>
-{
-  typedef _const_range_ptr_list<T> _base_type;
-  typedef T value_type;
-  typedef _ptr_list_iterator<T> iterator;
-  typedef T& reference;
-  typedef T* pointer;
-  typedef std::reverse_iterator<iterator> reverse_iterator;
-  typedef typename _base_type::const_iterator const_iterator;
-  typedef typename _base_type::const_reference const_reference;
-  typedef typename _base_type::const_pointer const_pointer;
-  typedef typename _base_type::const_reverse_iterator const_reverse_iterator;
-  typedef std::size_t size_type;
-  typedef std::ptrdiff_t difference_type;
-
-  typedef Eina_List* native_handle_type;
-  typedef _mutable_range_ptr_list<T> _self_type;
-
-  _mutable_range_ptr_list(native_handle_type list)
-    : _base_type(list) {}
-
-  native_handle_type native_handle() const
+  template <typename T>
+  static _ptr_list_iterator<T const> cbegin(Eina_List const* list)
+  {
+    return _ptr_list_access_traits::begin<T>(list);
+  }
+  template <typename T>
+  static _ptr_list_iterator<T const> cend(Eina_List const* list)
+  {
+    return _ptr_list_access_traits::end<T>(list);
+  }
+  template <typename T>
+  static std::reverse_iterator<_ptr_list_iterator<T const> > crbegin(Eina_List const* list)
+  {
+    return _ptr_list_access_traits::rbegin<T>(list);
+  }
+  template <typename T>
+  static std::reverse_iterator<_ptr_list_iterator<T const> > crend(Eina_List const* list)
+  {
+    return _ptr_list_access_traits::rend<T>(list);
+  }
+  template <typename T>
+  static eina::iterator<T> ibegin(Eina_List* list)
+  {
+    return eina::iterator<T>( ::eina_list_iterator_new(list) );
+  }
+  template <typename T>
+  static eina::iterator<T> iend(Eina_List*)
   {
-    return const_cast<native_handle_type>(_base_type::native_handle());
+    return eina::iterator<T>();
   }
-  value_type& back() const
+  template <typename T>
+  static eina::iterator<T const> ibegin(Eina_List const* list)
   {
-    return _ptr_list_access_traits::back<value_type>(native_handle());
+    return eina::iterator<T const>( ::eina_list_iterator_new(list) );
   }
-  value_type& front() const
+  template <typename T>
+  static eina::iterator<T const> iend(Eina_List const*)
   {
-    return _ptr_list_access_traits::front<value_type>(native_handle());
+    return eina::iterator<T const>();
   }
-  iterator begin() const
+  template <typename T>
+  static eina::iterator<T const> cibegin(Eina_List const* list)
   {
-    return _ptr_list_access_traits::begin<value_type>(native_handle());
+    return _ptr_list_access_traits::ibegin<T>(list);
   }
-  iterator end() const
+  template <typename T>
+  static eina::iterator<T const> ciend(Eina_List const* list)
   {
-    return _ptr_list_access_traits::end<value_type>(native_handle());
+    return _ptr_list_access_traits::iend<T>(list);
   }
-  reverse_iterator rbegin() const
+  template <typename T>
+  static std::size_t size(Eina_List const* list)
   {
-    return _ptr_list_access_traits::rbegin<value_type>(native_handle());
+    return eina_list_count(list);
   }
-  reverse_iterator rend() const
+  template <typename T>
+  static bool empty(Eina_List const* list)
   {
-    return _ptr_list_access_traits::rend<value_type>(native_handle());
+    return _ptr_list_access_traits::size<T>(list) == 0u;
   }
 };
 

diff --git a/src/bindings/eina_cxx/eina_range_types.hh b/src/bindings/eina_cxx/eina_range_types.hh
index 8216ade..4c60221 100644 (file)
--- a/src/bindings/eina_cxx/eina_range_types.hh
+++ b/src/bindings/eina_cxx/eina_range_types.hh
@@ -389,6 +389,7 @@ struct _range_template : private std::conditional
   using _base_type::crend;
   using _base_type::empty;
   using _base_type::size;
+  using _base_type::swap;
 protected:
   using _base_type::_handle;
 };