2013-08-06 Paolo Carlini <paolo.carlini@oracle.com>
[gcc.git] / libstdc++-v3 / include / bits / hashtable.h
index 43c89b1ce515608b1b99d848fa525ff9afa4bd7e..44ce3b30ef8d64f9e07d1328abb8ea9f69afa900 100644 (file)
@@ -103,7 +103,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *  Each _Hashtable data structure has:
    *
    *  - _Bucket[]       _M_buckets
-   *  - _Hash_node_base _M_before_begin
+   *  - _Hash_node_base _M_bbegin
    *  - size_type       _M_bucket_count
    *  - size_type       _M_element_count
    *
@@ -181,26 +181,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       public __detail::_Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
                                    _H1, _H2, _Hash, _RehashPolicy, _Traits>,
       public __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
-                                _H1, _H2, _Hash, _RehashPolicy, _Traits>,
-      private __detail::_Hashtable_alloc<
-       typename __alloctr_rebind<_Alloc,
-         __detail::_Hash_node<_Value,
-                              _Traits::__hash_cached::value> >::__type>
+                                _H1, _H2, _Hash, _RehashPolicy, _Traits>
     {
-      using __traits_type = _Traits;
-      using __hash_cached = typename __traits_type::__hash_cached;
-      using __node_type = __detail::_Hash_node<_Value, __hash_cached::value>;
-      using __node_alloc_type =
-       typename __alloctr_rebind<_Alloc, __node_type>::__type;
-
-      using __hashtable_alloc = __detail::_Hashtable_alloc<__node_alloc_type>;
-
-      using __value_alloc_traits =
-       typename __hashtable_alloc::__value_alloc_traits;
-      using __node_alloc_traits =
-       typename __hashtable_alloc::__node_alloc_traits;
-      using __node_base = typename __hashtable_alloc::__node_base;
-      using __bucket_type = typename __hashtable_alloc::__bucket_type;
+      typedef std::allocator_traits<_Alloc> _Alloc_traits;
+      typedef typename _Alloc_traits::template rebind_alloc<_Value>
+                                                       _Value_alloc_type;
+      typedef __gnu_cxx::__alloc_traits<_Value_alloc_type> _Value_alloc_traits;
 
     public:
       typedef _Key                                             key_type;
@@ -210,8 +196,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       // mapped_type, if present, comes from _Map_base.
       // hasher, if present, comes from _Hash_code_base/_Hashtable_base.
-      typedef typename __value_alloc_traits::pointer           pointer;
-      typedef typename __value_alloc_traits::const_pointer     const_pointer;
+      typedef typename _Value_alloc_traits::pointer            pointer;
+      typedef typename _Value_alloc_traits::const_pointer      const_pointer;
       typedef value_type&                                      reference;
       typedef const value_type&                                        const_reference;
 
@@ -219,6 +205,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       using __rehash_type = _RehashPolicy;
       using __rehash_state = typename __rehash_type::_State;
 
+      using __traits_type = _Traits;
+      using __hash_cached = typename __traits_type::__hash_cached;
       using __constant_iterators = typename __traits_type::__constant_iterators;
       using __unique_keys = typename __traits_type::__unique_keys;
 
@@ -233,6 +221,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       using __hash_code_base =  typename __hashtable_base::__hash_code_base;
       using __hash_code =  typename __hashtable_base::__hash_code;
+      using __node_type = typename __hashtable_base::__node_type;
+      using __node_base = typename __hashtable_base::__node_base;
+      using __bucket_type = typename __hashtable_base::__bucket_type;
       using __ireturn_type = typename __hashtable_base::__ireturn_type;
 
       using __map_base = __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey,
@@ -249,7 +240,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
                                            _RehashPolicy, _Traits>;
 
       using __reuse_or_alloc_node_type =
-       __detail::_ReuseOrAllocNode<__node_alloc_type>;
+       __detail::_ReuseOrAllocNode<_Key, _Value, _Alloc,
+                                   _ExtractKey, _Equal, _H1, _H2, _Hash,
+                                   _RehashPolicy, _Traits>;
 
       // Metaprogramming for picking apart hash caching.
       template<typename _Cond>
@@ -316,6 +309,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               bool _Constant_iteratorsa, bool _Unique_keysa>
        friend struct __detail::_Insert;
 
+      template<typename _Keya, typename _Valuea, typename _Alloca,
+              typename _ExtractKeya, typename _Equala,
+              typename _H1a, typename _H2a, typename _Hasha,
+              typename _RehashPolicya, typename _Traitsa>
+       friend struct __detail::_ReuseOrAllocNode;
+
+      template<typename _Keya, typename _Valuea, typename _Alloca,
+              typename _ExtractKeya, typename _Equala,
+              typename _H1a, typename _H2a, typename _Hasha,
+              typename _RehashPolicya, typename _Traitsa>
+       friend struct __detail::_AllocNode;
+
     public:
       using size_type = typename __hashtable_base::size_type;
       using difference_type = typename __hashtable_base::difference_type;
@@ -328,20 +333,60 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
                                   const_local_iterator;
 
     private:
+      typedef typename _Alloc_traits::template rebind_alloc<__node_type>
+                                                       _Node_alloc_type;
+      // Use __gnu_cxx to benefit from _S_always_equal and al.
+      typedef __gnu_cxx::__alloc_traits<_Node_alloc_type> _Node_alloc_traits;
+
+      typedef
+      typename _Alloc_traits::template rebind_alloc<__bucket_type>
+                                                       _Bucket_alloc_type;
+      typedef std::allocator_traits<_Bucket_alloc_type> _Bucket_alloc_traits;
+
+      using __before_begin = __detail::_Before_begin<_Node_alloc_type>;
+
       __bucket_type*           _M_buckets;
       size_type                        _M_bucket_count;
-      __node_base              _M_before_begin;
+      __before_begin           _M_bbegin;
       size_type                        _M_element_count;
       _RehashPolicy            _M_rehash_policy;
 
-      __hashtable_alloc&
-      _M_base_alloc() { return *this; }
+      _Node_alloc_type&
+      _M_node_allocator()
+      { return _M_bbegin; }
+
+      const _Node_alloc_type&
+      _M_node_allocator() const
+      { return _M_bbegin; }
+
+      __node_base&
+      _M_before_begin()
+      { return _M_bbegin._M_node; }
+
+      const __node_base&
+      _M_before_begin() const
+      { return _M_bbegin._M_node; }
 
-      using __hashtable_alloc::_M_deallocate_buckets;
+      template<typename... _Args>
+       __node_type*
+       _M_allocate_node(_Args&&... __args);
+
+      void
+      _M_deallocate_node(__node_type* __n);
+
+      // Deallocate the linked list of nodes pointed to by __n
+      void
+      _M_deallocate_nodes(__node_type* __n);
+
+      __bucket_type*
+      _M_allocate_buckets(size_type __n);
+
+      void
+      _M_deallocate_buckets(__bucket_type*, size_type __n);
 
       void
       _M_deallocate_buckets()
-      { this->_M_deallocate_buckets(_M_buckets, _M_bucket_count); }
+      { _M_deallocate_buckets(_M_buckets, _M_bucket_count); }
 
       // Gets bucket begin, deals with the fact that non-empty buckets contain
       // their before begin node.
@@ -350,7 +395,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       __node_type*
       _M_begin() const
-      { return static_cast<__node_type*>(_M_before_begin._M_nxt); }
+      { return static_cast<__node_type*>(_M_before_begin()._M_nxt); }
 
       template<typename _NodeGenerator>
        void
@@ -432,11 +477,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       _Hashtable&
       operator=(_Hashtable&& __ht)
-      noexcept(__node_alloc_traits::_S_nothrow_move())
+      noexcept(_Node_alloc_traits::_S_nothrow_move())
       {
         constexpr bool __move_storage =
-          __node_alloc_traits::_S_propagate_on_move_assign()
-          || __node_alloc_traits::_S_always_equal();
+          _Node_alloc_traits::_S_propagate_on_move_assign()
+          || _Node_alloc_traits::_S_always_equal();
         _M_move_assign(std::move(__ht),
                        integral_constant<bool, __move_storage>());
        return *this;
@@ -446,7 +491,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       operator=(initializer_list<value_type> __l)
       {
        __reuse_or_alloc_node_type __roan(_M_begin(), *this);
-       _M_before_begin._M_nxt = nullptr;
+       _M_before_begin()._M_nxt = nullptr;
        clear();
        this->_M_insert_range(__l.begin(), __l.end(), __roan);
        return *this;
@@ -456,7 +501,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       void
       swap(_Hashtable&)
-      noexcept(__node_alloc_traits::_S_nothrow_swap());
+      noexcept(_Node_alloc_traits::_S_nothrow_swap());
 
       // Basic container operations
       iterator
@@ -493,11 +538,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       allocator_type
       get_allocator() const noexcept
-      { return allocator_type(this->_M_node_allocator()); }
+      { return allocator_type(_M_node_allocator()); }
 
       size_type
       max_size() const noexcept
-      { return __node_alloc_traits::max_size(this->_M_node_allocator()); }
+      { return _Node_alloc_traits::max_size(_M_node_allocator()); }
 
       // Observers
       key_equal
@@ -758,6 +803,101 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 
   // Definitions of class template _Hashtable's out-of-line member functions.
+  template<typename _Key, typename _Value,
+          typename _Alloc, typename _ExtractKey, typename _Equal,
+          typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
+          typename _Traits>
+    template<typename... _Args>
+      typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
+                         _H1, _H2, _Hash, _RehashPolicy, _Traits>::__node_type*
+      _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
+                _H1, _H2, _Hash, _RehashPolicy, _Traits>::
+      _M_allocate_node(_Args&&... __args)
+      {
+       auto __nptr = _Node_alloc_traits::allocate(_M_node_allocator(), 1);
+       __node_type* __n = std::__addressof(*__nptr);
+       __try
+         {
+           _Value_alloc_type __a(_M_node_allocator());
+           ::new ((void*)__n) __node_type();
+           _Value_alloc_traits::construct(__a, __n->_M_valptr(),
+                                          std::forward<_Args>(__args)...);
+           return __n;
+         }
+       __catch(...)
+         {
+           _Node_alloc_traits::deallocate(_M_node_allocator(), __nptr, 1);
+           __throw_exception_again;
+         }
+      }
+
+  template<typename _Key, typename _Value,
+          typename _Alloc, typename _ExtractKey, typename _Equal,
+          typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
+          typename _Traits>
+    void
+    _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
+              _H1, _H2, _Hash, _RehashPolicy, _Traits>::
+    _M_deallocate_node(__node_type* __n)
+    {
+      typedef typename _Node_alloc_traits::pointer _Ptr;
+      auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__n);
+      _Value_alloc_type __a(_M_node_allocator());
+      _Value_alloc_traits::destroy(__a, __n->_M_valptr());
+      __n->~__node_type();
+      _Node_alloc_traits::deallocate(_M_node_allocator(), __ptr, 1);
+    }
+
+  template<typename _Key, typename _Value,
+          typename _Alloc, typename _ExtractKey, typename _Equal,
+          typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
+          typename _Traits>
+    void
+    _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
+              _H1, _H2, _Hash, _RehashPolicy, _Traits>::
+    _M_deallocate_nodes(__node_type* __n)
+    {
+      while (__n)
+       {
+         __node_type* __tmp = __n;
+         __n = __n->_M_next();
+         _M_deallocate_node(__tmp);
+       }
+    }
+
+  template<typename _Key, typename _Value,
+          typename _Alloc, typename _ExtractKey, typename _Equal,
+          typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
+          typename _Traits>
+    typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
+                       _H1, _H2, _Hash, _RehashPolicy, _Traits>::__bucket_type*
+    _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
+              _H1, _H2, _Hash, _RehashPolicy, _Traits>::
+    _M_allocate_buckets(size_type __n)
+    {
+      _Bucket_alloc_type __alloc(_M_node_allocator());
+
+      auto __ptr = _Bucket_alloc_traits::allocate(__alloc, __n);
+      __bucket_type* __p = std::__addressof(*__ptr);
+      __builtin_memset(__p, 0, __n * sizeof(__bucket_type));
+      return __p;
+    }
+
+  template<typename _Key, typename _Value,
+          typename _Alloc, typename _ExtractKey, typename _Equal,
+          typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
+          typename _Traits>
+    void
+    _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
+              _H1, _H2, _Hash, _RehashPolicy, _Traits>::
+    _M_deallocate_buckets(__bucket_type* __bkts, size_type __n)
+    {
+      typedef typename _Bucket_alloc_traits::pointer _Ptr;
+      auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__bkts);
+      _Bucket_alloc_type __alloc(_M_node_allocator());
+      _Bucket_alloc_traits::deallocate(__alloc, __ptr, __n);
+    }
+
   template<typename _Key, typename _Value,
           typename _Alloc, typename _ExtractKey, typename _Equal,
           typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
@@ -786,12 +926,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     : __hashtable_base(__exk, __h1, __h2, __h, __eq),
       __map_base(),
       __rehash_base(),
-      __hashtable_alloc(__node_alloc_type(__a)),
+      _M_bbegin(__a),
       _M_element_count(0),
       _M_rehash_policy()
     {
       _M_bucket_count = _M_rehash_policy._M_next_bkt(__bucket_hint);
-      _M_buckets = this->_M_allocate_buckets(_M_bucket_count);
+      _M_buckets = _M_allocate_buckets(_M_bucket_count);
     }
 
   template<typename _Key, typename _Value,
@@ -809,7 +949,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       : __hashtable_base(__exk, __h1, __h2, __h, __eq),
        __map_base(),
        __rehash_base(),
-       __hashtable_alloc(__node_alloc_type(__a)),
+       _M_bbegin(__a),
        _M_element_count(0),
        _M_rehash_policy()
       {
@@ -819,7 +959,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
            std::max(_M_rehash_policy._M_bkt_for_elements(__nb_elems),
                     __bucket_hint));
 
-       _M_buckets = this->_M_allocate_buckets(_M_bucket_count);
+       _M_buckets = _M_allocate_buckets(_M_bucket_count);
        __try
          {
            for (; __f != __l; ++__f)
@@ -847,15 +987,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        if (&__ht == this)
          return *this;
 
-       if (__node_alloc_traits::_S_propagate_on_copy_assign())
+       if (_Node_alloc_traits::_S_propagate_on_copy_assign())
          {
            auto& __this_alloc = this->_M_node_allocator();
            auto& __that_alloc = __ht._M_node_allocator();
-           if (!__node_alloc_traits::_S_always_equal()
+           if (!_Node_alloc_traits::_S_always_equal()
                && __this_alloc != __that_alloc)
              {
                // Replacement allocator cannot free existing storage.
-               this->_M_deallocate_nodes(_M_begin());
+               _M_deallocate_nodes(_M_begin());
                if (__builtin_expect(_M_bucket_count != 0, true))
                  _M_deallocate_buckets();
                _M_reset();
@@ -868,7 +1008,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
                  {
                    _M_assign(__ht,
                              [this](const __node_type* __n)
-                             { return this->_M_allocate_node(__n->_M_v()); });
+                             { return _M_allocate_node(__n->_M_v()); });
                  }
                __catch(...)
                  {
@@ -890,7 +1030,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        if (_M_bucket_count != __ht._M_bucket_count)
          {
            __former_buckets = _M_buckets;
-           _M_buckets = this->_M_allocate_buckets(__ht._M_bucket_count);
+           _M_buckets = _M_allocate_buckets(__ht._M_bucket_count);
            _M_bucket_count = __ht._M_bucket_count;
          }
        else
@@ -903,13 +1043,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
            _M_element_count = __ht._M_element_count;
            _M_rehash_policy = __ht._M_rehash_policy;
            __reuse_or_alloc_node_type __roan(_M_begin(), *this);
-           _M_before_begin._M_nxt = nullptr;
+           _M_before_begin()._M_nxt = nullptr;
            _M_assign(__ht, 
                      [&__roan](const __node_type* __n)
                      { return __roan(__n->_M_v()); });
            if (__former_buckets)
-             this->_M_deallocate_buckets(__former_buckets,
-                                         __former_bucket_count);
+             _M_deallocate_buckets(__former_buckets, __former_bucket_count);
          }
        __catch(...)
          {
@@ -940,11 +1079,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       {
        __bucket_type* __buckets = nullptr;
        if (!_M_buckets)
-         _M_buckets = __buckets = this->_M_allocate_buckets(_M_bucket_count);
+         _M_buckets = __buckets = _M_allocate_buckets(_M_bucket_count);
 
        __try
          {
-           if (!__ht._M_before_begin._M_nxt)
+           if (!__ht._M_before_begin()._M_nxt)
              return;
 
            // First deal with the special first node pointed to by
@@ -952,8 +1091,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
            __node_type* __ht_n = __ht._M_begin();
            __node_type* __this_n = __node_gen(__ht_n);
            this->_M_copy_code(__this_n, __ht_n);
-           _M_before_begin._M_nxt = __this_n;
-           _M_buckets[_M_bucket_index(__this_n)] = &_M_before_begin;
+           _M_before_begin()._M_nxt = __this_n;
+           _M_buckets[_M_bucket_index(__this_n)] = &_M_before_begin();
 
            // Then deal with other nodes.
            __node_base* __prev_n = __this_n;
@@ -989,7 +1128,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _M_rehash_policy._M_reset();
       _M_bucket_count = 0;
       _M_buckets = nullptr;
-      _M_before_begin._M_nxt = nullptr;
+      _M_before_begin()._M_nxt = nullptr;
       _M_element_count = 0;
     }
 
@@ -1002,7 +1141,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     _M_move_assign(_Hashtable&& __ht, std::true_type)
     {
-      this->_M_deallocate_nodes(_M_begin());
+      _M_deallocate_nodes(_M_begin());
       if (__builtin_expect(_M_bucket_count != 0, true))
        _M_deallocate_buckets();
 
@@ -1010,14 +1149,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _M_rehash_policy = __ht._M_rehash_policy;
       _M_buckets = __ht._M_buckets;
       _M_bucket_count = __ht._M_bucket_count;
-      _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt;
+      _M_before_begin()._M_nxt = __ht._M_before_begin()._M_nxt;
       _M_element_count = __ht._M_element_count;
-      std::__alloc_on_move(this->_M_node_allocator(), __ht._M_node_allocator());
+      std::__alloc_on_move(_M_node_allocator(), __ht._M_node_allocator());
 
       // Fix buckets containing the _M_before_begin pointers that can't be
       // moved.
       if (_M_begin())
-       _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
+       _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin();
       __ht._M_reset();
     }
 
@@ -1030,7 +1169,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     _M_move_assign(_Hashtable&& __ht, std::false_type)
     {
-      if (__ht._M_node_allocator() == this->_M_node_allocator())
+      if (__ht._M_node_allocator() == _M_node_allocator())
        _M_move_assign(std::move(__ht), std::true_type());
       else
        {
@@ -1042,7 +1181,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          if (_M_bucket_count != __ht._M_bucket_count)
            {
              __former_buckets = _M_buckets;
-             _M_buckets = this->_M_allocate_buckets(__ht._M_bucket_count);
+             _M_buckets = _M_allocate_buckets(__ht._M_bucket_count);
              _M_bucket_count = __ht._M_bucket_count;
            }
          else
@@ -1055,7 +1194,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
              _M_element_count = __ht._M_element_count;
              _M_rehash_policy = __ht._M_rehash_policy;
              __reuse_or_alloc_node_type __roan(_M_begin(), *this);
-             _M_before_begin._M_nxt = nullptr;
+             _M_before_begin()._M_nxt = nullptr;
              _M_assign(__ht,
                        [&__roan](__node_type* __n)
                        { return __roan(std::move_if_noexcept(__n->_M_v())); });
@@ -1087,16 +1226,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     : __hashtable_base(__ht),
       __map_base(__ht),
       __rehash_base(__ht),
-      __hashtable_alloc(
-       __node_alloc_traits::_S_select_on_copy(__ht._M_node_allocator())),
       _M_buckets(),
       _M_bucket_count(__ht._M_bucket_count),
+      _M_bbegin(_Node_alloc_traits::_S_select_on_copy(
+               __ht._M_node_allocator())),
       _M_element_count(__ht._M_element_count),
       _M_rehash_policy(__ht._M_rehash_policy)
     {
       _M_assign(__ht,
                [this](const __node_type* __n)
-               { return this->_M_allocate_node(__n->_M_v()); });
+               { return _M_allocate_node(__n->_M_v()); });
     }
 
   template<typename _Key, typename _Value,
@@ -1109,17 +1248,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     : __hashtable_base(__ht),
       __map_base(__ht),
       __rehash_base(__ht),
-      __hashtable_alloc(std::move(__ht._M_base_alloc())),
       _M_buckets(__ht._M_buckets),
       _M_bucket_count(__ht._M_bucket_count),
-      _M_before_begin(__ht._M_before_begin._M_nxt),
+      _M_bbegin(std::move(__ht._M_bbegin)),
       _M_element_count(__ht._M_element_count),
       _M_rehash_policy(__ht._M_rehash_policy)
     {
       // Update, if necessary, bucket pointing to before begin that hasn't
       // moved.
       if (_M_begin())
-       _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
+       _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin();
       __ht._M_reset();
     }
 
@@ -1133,15 +1271,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     : __hashtable_base(__ht),
       __map_base(__ht),
       __rehash_base(__ht),
-      __hashtable_alloc(__node_alloc_type(__a)),
       _M_buckets(),
       _M_bucket_count(__ht._M_bucket_count),
+      _M_bbegin(_Node_alloc_type(__a)),
       _M_element_count(__ht._M_element_count),
       _M_rehash_policy(__ht._M_rehash_policy)
     {
       _M_assign(__ht,
                [this](const __node_type* __n)
-               { return this->_M_allocate_node(__n->_M_v()); });
+               { return _M_allocate_node(__n->_M_v()); });
     }
 
   template<typename _Key, typename _Value,
@@ -1154,20 +1292,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     : __hashtable_base(__ht),
       __map_base(__ht),
       __rehash_base(__ht),
-      __hashtable_alloc(__node_alloc_type(__a)),
       _M_buckets(),
       _M_bucket_count(__ht._M_bucket_count),
+      _M_bbegin(_Node_alloc_type(__a)),
       _M_element_count(__ht._M_element_count),
       _M_rehash_policy(__ht._M_rehash_policy)
     {
-      if (__ht._M_node_allocator() == this->_M_node_allocator())
+      if (__ht._M_node_allocator() == _M_node_allocator())
        {
          _M_buckets = __ht._M_buckets;
-         _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt;
+         _M_before_begin()._M_nxt = __ht._M_before_begin()._M_nxt;
          // Update, if necessary, bucket pointing to before begin that hasn't
          // moved.
          if (_M_begin())
-           _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
+           _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin();
          __ht._M_reset();
        }
       else
@@ -1175,7 +1313,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          _M_assign(__ht,
                    [this](__node_type* __n)
                    {
-                     return this->_M_allocate_node(
+                     return _M_allocate_node(
                                        std::move_if_noexcept(__n->_M_v()));
                    });
          __ht.clear();
@@ -1203,27 +1341,27 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     swap(_Hashtable& __x)
-    noexcept(__node_alloc_traits::_S_nothrow_swap())
+    noexcept(_Node_alloc_traits::_S_nothrow_swap())
     {
       // The only base class with member variables is hash_code_base.
       // We define _Hash_code_base::_M_swap because different
       // specializations have different members.
       this->_M_swap(__x);
 
-      std::__alloc_on_swap(this->_M_node_allocator(), __x._M_node_allocator());
+      std::__alloc_on_swap(_M_node_allocator(), __x._M_node_allocator());
       std::swap(_M_rehash_policy, __x._M_rehash_policy);
       std::swap(_M_buckets, __x._M_buckets);
       std::swap(_M_bucket_count, __x._M_bucket_count);
-      std::swap(_M_before_begin._M_nxt, __x._M_before_begin._M_nxt);
+      std::swap(_M_before_begin()._M_nxt, __x._M_before_begin()._M_nxt);
       std::swap(_M_element_count, __x._M_element_count);
 
       // Fix buckets containing the _M_before_begin pointers that can't be
       // swapped.
       if (_M_begin())
-       _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
+       _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin();
       if (__x._M_begin())
        __x._M_buckets[__x._M_bucket_index(__x._M_begin())]
-         = &__x._M_before_begin;
+         = &(__x._M_before_begin());
     }
 
   template<typename _Key, typename _Value,
@@ -1442,13 +1580,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          // The bucket is empty, the new node is inserted at the
          // beginning of the singly-linked list and the bucket will
          // contain _M_before_begin pointer.
-         __node->_M_nxt = _M_before_begin._M_nxt;
-         _M_before_begin._M_nxt = __node;
+         __node->_M_nxt = _M_before_begin()._M_nxt;
+         _M_before_begin()._M_nxt = __node;
          if (__node->_M_nxt)
            // We must update former begin bucket that is pointing to
            // _M_before_begin.
            _M_buckets[_M_bucket_index(__node->_M_next())] = __node;
-         _M_buckets[__bkt] = &_M_before_begin;
+         _M_buckets[__bkt] = &_M_before_begin();
        }
     }
 
@@ -1470,8 +1608,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
            _M_buckets[__next_bkt] = _M_buckets[__bkt];
 
          // Second update before begin node if necessary
-         if (&_M_before_begin == _M_buckets[__bkt])
-           _M_before_begin._M_nxt = __next;
+         if (&_M_before_begin() == _M_buckets[__bkt])
+           _M_before_begin()._M_nxt = __next;
          _M_buckets[__bkt] = nullptr;
        }
     }
@@ -1507,7 +1645,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _M_emplace(std::true_type, _Args&&... __args)
       {
        // First build the node to get access to the hash code
-       __node_type* __node = this->_M_allocate_node(std::forward<_Args>(__args)...);
+       __node_type* __node = _M_allocate_node(std::forward<_Args>(__args)...);
        const key_type& __k = this->_M_extract()(__node->_M_v());
        __hash_code __code;
        __try
@@ -1516,7 +1654,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          }
        __catch(...)
          {
-           this->_M_deallocate_node(__node);
+           _M_deallocate_node(__node);
            __throw_exception_again;
          }
 
@@ -1524,7 +1662,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        if (__node_type* __p = _M_find_node(__bkt, __k, __code))
          {
            // There is already an equivalent node, no insertion
-           this->_M_deallocate_node(__node);
+           _M_deallocate_node(__node);
            return std::make_pair(iterator(__p), false);
          }
 
@@ -1546,8 +1684,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _M_emplace(const_iterator __hint, std::false_type, _Args&&... __args)
       {
        // First build the node to get its hash code.
-       __node_type* __node =
-         this->_M_allocate_node(std::forward<_Args>(__args)...);
+       __node_type* __node = _M_allocate_node(std::forward<_Args>(__args)...);
 
        __hash_code __code;
        __try
@@ -1556,7 +1693,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          }
        __catch(...)
          {
-           this->_M_deallocate_node(__node);
+           _M_deallocate_node(__node);
            __throw_exception_again;
          }
 
@@ -1596,7 +1733,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        }
       __catch(...)
        {
-         this->_M_deallocate_node(__node);
+         _M_deallocate_node(__node);
          __throw_exception_again;
        }
     }
@@ -1662,7 +1799,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        }
       __catch(...)
        {
-         this->_M_deallocate_node(__node);
+         _M_deallocate_node(__node);
          __throw_exception_again;
        }
     }
@@ -1762,7 +1899,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       __prev_n->_M_nxt = __n->_M_nxt;
       iterator __result(__n->_M_next());
-      this->_M_deallocate_node(__n);
+      _M_deallocate_node(__n);
       --_M_element_count;
 
       return __result;
@@ -1835,7 +1972,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       do
        {
          __node_type* __p = __n->_M_next();
-         this->_M_deallocate_node(__n);
+         _M_deallocate_node(__n);
          __n = __p;
          ++__result;
          --_M_element_count;
@@ -1877,7 +2014,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
            {
              __node_type* __tmp = __n;
              __n = __n->_M_next();
-             this->_M_deallocate_node(__tmp);
+             _M_deallocate_node(__tmp);
              --_M_element_count;
              if (!__n)
                break;
@@ -1907,10 +2044,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     clear() noexcept
     {
-      this->_M_deallocate_nodes(_M_begin());
+      _M_deallocate_nodes(_M_begin());
       __builtin_memset(_M_buckets, 0, _M_bucket_count * sizeof(__bucket_type));
       _M_element_count = 0;
-      _M_before_begin._M_nxt = nullptr;
+      _M_before_begin()._M_nxt = nullptr;
     }
 
   template<typename _Key, typename _Value,
@@ -1967,9 +2104,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     _M_rehash_aux(size_type __n, std::true_type)
     {
-      __bucket_type* __new_buckets = this->_M_allocate_buckets(__n);
+      __bucket_type* __new_buckets = _M_allocate_buckets(__n);
       __node_type* __p = _M_begin();
-      _M_before_begin._M_nxt = nullptr;
+      _M_before_begin()._M_nxt = nullptr;
       std::size_t __bbegin_bkt = 0;
       while (__p)
        {
@@ -1977,9 +2114,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n);
          if (!__new_buckets[__bkt])
            {
-             __p->_M_nxt = _M_before_begin._M_nxt;
-             _M_before_begin._M_nxt = __p;
-             __new_buckets[__bkt] = &_M_before_begin;
+             __p->_M_nxt = _M_before_begin()._M_nxt;
+             _M_before_begin()._M_nxt = __p;
+             __new_buckets[__bkt] = &_M_before_begin();
              if (__p->_M_nxt)
                __new_buckets[__bbegin_bkt] = __p;
              __bbegin_bkt = __bkt;
@@ -2009,10 +2146,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     _M_rehash_aux(size_type __n, std::false_type)
     {
-      __bucket_type* __new_buckets = this->_M_allocate_buckets(__n);
+      __bucket_type* __new_buckets = _M_allocate_buckets(__n);
 
       __node_type* __p = _M_begin();
-      _M_before_begin._M_nxt = nullptr;
+      _M_before_begin()._M_nxt = nullptr;
       std::size_t __bbegin_bkt = 0;
       std::size_t __prev_bkt = 0;
       __node_type* __prev_p = nullptr;
@@ -2057,9 +2194,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
              if (!__new_buckets[__bkt])
                {
-                 __p->_M_nxt = _M_before_begin._M_nxt;
-                 _M_before_begin._M_nxt = __p;
-                 __new_buckets[__bkt] = &_M_before_begin;
+                 __p->_M_nxt = _M_before_begin()._M_nxt;
+                 _M_before_begin()._M_nxt = __p;
+                 __new_buckets[__bkt] = &_M_before_begin();
                  if (__p->_M_nxt)
                    __new_buckets[__bbegin_bkt] = __p;
                  __bbegin_bkt = __bkt;