[Boost-commit] svn:boost r45694 - trunk/boost/interprocess/detail

From: igaztanaga_at_[hidden]
Date: 2008-05-23 18:25:37

Author: igaztanaga
Date: 2008-05-23 18:25:35 EDT (Fri, 23 May 2008)
New Revision: 45694
URL: http://svn.boost.org/trac/boost/changeset/45694

Log:
#1912: some copy edits on boost.intrusive
#1932: move semantics for shared objects
#1635: Incomplete include guard in boost/intrusive
Added:
   trunk/boost/interprocess/detail/intersegment_ptr.hpp   (contents, props changed)

Added: trunk/boost/interprocess/detail/intersegment_ptr.hpp
==============================================================================
--- (empty file)
+++ trunk/boost/interprocess/detail/intersegment_ptr.hpp	2008-05-23 18:25:35 EDT (Fri, 23 May 2008)
@@ -0,0 +1,1054 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2005-2008. 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)
+//
+// See http://www.boost.org/libs/interprocess for documentation.
+//
+//////////////////////////////////////////////////////////////////////////////
+
+#ifndef BOOST_INTERPROCESS_INTERSEGMENT_PTR_HPP
+#define BOOST_INTERPROCESS_INTERSEGMENT_PTR_HPP
+
+#if (defined _MSC_VER) && (_MSC_VER >= 1200)
+#  pragma once
+#endif
+
+#include <boost/interprocess/detail/config_begin.hpp>
+#include <boost/interprocess/detail/workaround.hpp>
+
+#include <boost/interprocess/interprocess_fwd.hpp>
+#include <boost/interprocess/detail/utilities.hpp>
+#include <boost/interprocess/detail/math_functions.hpp>
+#include <boost/interprocess/detail/cast_tags.hpp>
+#include <boost/assert.hpp>
+#include <boost/interprocess/sync/scoped_lock.hpp>
+#include <boost/interprocess/sync/interprocess_mutex.hpp>
+#include <boost/interprocess/containers/flat_map.hpp>
+#include <boost/interprocess/containers/vector.hpp>   //vector
+#include <boost/interprocess/containers/set.hpp>      //set
+#include <boost/detail/no_exceptions_support.hpp>
+#include <boost/interprocess/detail/mpl.hpp>
+#include <climits>
+#include <iterator>
+#include <boost/static_assert.hpp>  //BOOST_STATIC_ASSERT
+#include <climits>   //CHAR_BIT
+#include <boost/integer/static_log2.hpp>
+#include <cassert>   //assert
+#include <boost/interprocess/detail/multi_segment_services.hpp>
+
+//!\file
+//!
+namespace boost {
+
+//Predeclarations
+template <class T>
+struct has_trivial_constructor;
+
+template <class T>
+struct has_trivial_destructor;
+
+namespace interprocess {
+
+template <class T>
+struct is_multisegment_ptr;
+
+struct intersegment_base
+{
+   typedef intersegment_base  self_t;
+   BOOST_STATIC_ASSERT((sizeof(std::size_t) == sizeof(void*)));
+   BOOST_STATIC_ASSERT((sizeof(void*)*CHAR_BIT == 32 || sizeof(void*)*CHAR_BIT == 64));
+   static const std::size_t size_t_bits = (sizeof(void*)*CHAR_BIT == 32) ? 32 : 64;
+   static const std::size_t ctrl_bits = 2;
+   static const std::size_t align_bits = 12;
+   static const std::size_t align      = std::size_t(1) << align_bits;
+   static const std::size_t max_segment_size_bits = size_t_bits - 2;
+   static const std::size_t max_segment_size = std::size_t(1) << max_segment_size_bits;
+
+   static const std::size_t begin_bits             = max_segment_size_bits - align_bits;
+   static const std::size_t pow_size_bits_helper = static_log2<max_segment_size_bits>::value;
+   static const std::size_t pow_size_bits = 
+      (max_segment_size_bits == (std::size_t(1) << pow_size_bits_helper)) ? 
+      pow_size_bits_helper : pow_size_bits_helper + 1;
+   static const std::size_t frc_size_bits =
+      size_t_bits - ctrl_bits - begin_bits - pow_size_bits;
+
+   BOOST_STATIC_ASSERT(((size_t_bits - pow_size_bits - frc_size_bits) >= ctrl_bits ));
+
+   static const std::size_t relative_size_bits =
+      size_t_bits - max_segment_size_bits - ctrl_bits;
+
+   static const std::size_t is_pointee_outside  = 0;
+   static const std::size_t is_in_stack         = 1;
+   static const std::size_t is_relative         = 2;
+   static const std::size_t is_segmented        = 3;
+   static const std::size_t is_max_mode         = 4;
+
+   intersegment_base()
+   {
+      this->set_mode(is_pointee_outside);
+      this->set_null();
+   }
+
+   struct relative_addressing
+   {
+      std::size_t ctrl     :  2;
+      std::size_t pow      :  pow_size_bits;
+      std::size_t frc      :  frc_size_bits;
+      std::size_t beg      :  begin_bits;
+      std::ptrdiff_t off   :  sizeof(ptrdiff_t)*CHAR_BIT - 2;
+      std::ptrdiff_t bits  :  2;
+   };
+
+   struct direct_addressing
+   {
+      std::size_t ctrl     :  2;
+      std::size_t dummy    :  sizeof(std::size_t)*CHAR_BIT - 2;
+      void * addr;
+   };
+
+   struct segmented_addressing
+   {
+      std::size_t ctrl     :  2;
+      std::size_t segment  :  sizeof(std::size_t)*CHAR_BIT - 2;
+      std::size_t off      :  sizeof(std::size_t)*CHAR_BIT - 2;
+      std::size_t bits     :  2;
+   };
+
+   union members_t{
+      relative_addressing  relative;
+      direct_addressing    direct;
+      segmented_addressing segmented;
+   } members;
+
+   BOOST_STATIC_ASSERT(sizeof(members_t) == 2*sizeof(std::size_t));
+
+   void *relative_calculate_begin_addr() const
+   {
+      const std::size_t mask = ~(align - 1);
+      std::size_t beg = this->members.relative.beg;
+      return (void*)((((std::size_t)this) & mask) - (beg << align_bits));
+   }
+
+   void relative_set_begin_from_base(void *addr)
+   {
+      assert(addr < (void*)this);
+      std::size_t off = (char*)this - (char*)addr;
+      members.relative.beg = off >> align_bits;
+   }
+
+   //!Obtains the address pointed by the
+   //!object
+   std::size_t relative_size() const
+   {
+      std::size_t pow  = members.relative.pow;
+      std::size_t size = (std::size_t(1u) << pow);
+      assert(pow >= frc_size_bits);
+      size |= members.relative.frc << (pow - frc_size_bits);
+      return size;
+   }
+
+   static std::size_t calculate_size(std::size_t orig_size, std::size_t &pow, std::size_t &frc)
+   {
+      if(orig_size < align)
+         orig_size = align;
+      orig_size = detail::get_rounded_size_po2(orig_size, align);
+      pow = detail::floor_log2(orig_size);
+      std::size_t low_size = (std::size_t(1) << pow);
+      std::size_t diff = orig_size - low_size;
+      assert(pow >= frc_size_bits);
+      std::size_t rounded = detail::get_rounded_size_po2
+                              (diff, (1u << (pow - frc_size_bits)));
+      if(rounded == low_size){
+         ++pow;
+         frc = 0;
+         rounded  = 0;
+      }
+      else{
+         frc = rounded >> (pow - frc_size_bits);
+      }
+      assert(((frc << (pow - frc_size_bits)) & (align-1))==0);
+      return low_size + rounded;
+   }
+
+   std::size_t get_mode()const
+   {  return members.direct.ctrl;   }
+
+   void set_mode(std::size_t mode)
+   {
+      assert(mode < is_max_mode);      
+      members.direct.ctrl = mode;
+   }
+
+   //!Returns true if object represents
+   //!null pointer
+   bool is_null() const
+   {
+      return   (this->get_mode() < is_relative) && 
+               !members.direct.dummy &&
+               !members.direct.addr;
+   }
+
+   //!Sets the object to represent
+   //!the null pointer
+   void set_null()
+   {
+      if(this->get_mode() >= is_relative){
+         this->set_mode(is_pointee_outside);
+      }
+      members.direct.dummy = 0;
+      members.direct.addr  = 0;
+   }
+
+   static std::size_t round_size(std::size_t orig_size)
+   {
+      std::size_t pow, frc;
+      return calculate_size(orig_size, pow, frc);
+   }
+};
+
+
+
+//!Configures intersegment_ptr with the capability to address:
+//!2^(sizeof(std::size_t)*CHAR_BIT/2) segment groups
+//!2^(sizeof(std::size_t)*CHAR_BIT/2) segments per group.
+//!2^(sizeof(std::size_t)*CHAR_BIT/2)-1 bytes maximum per segment.
+//!The mapping is implemented through flat_maps synchronized with mutexes.
+template <class Mutex>
+struct flat_map_intersegment
+   :  public intersegment_base
+{
+   typedef flat_map_intersegment<Mutex>   self_t;
+
+   void set_from_pointer(const volatile void *ptr)
+   {  this->set_from_pointer((const void *)ptr);  }
+
+   //!Obtains the address pointed
+   //!by the object
+   void *get_pointer() const
+   {
+      if(is_null()){
+         return 0;
+      }
+      switch(this->get_mode()){
+         case is_relative:
+            return (char*)this + members.relative.off;
+         break;
+         case is_segmented:
+            {
+            segment_info_t segment_info;
+            std::size_t offset;
+            void *this_base;
+            get_segment_info_and_offset(this, segment_info, offset, this_base);
+            char *base  = (char*)segment_info.group->address_of(this->members.segmented.segment);
+            return base + this->members.segmented.off;
+            }
+         break;
+         case is_in_stack:
+         case is_pointee_outside:
+            return members.direct.addr;
+         break;
+         default:
+         return 0;
+         break;
+      }
+   }
+
+   //!Calculates the distance between two basic_intersegment_ptr-s.
+   //!This only works with two basic_intersegment_ptr pointing
+   //!to the same segment. Otherwise undefined
+   std::ptrdiff_t diff(const self_t &other) const
+   {  return (char*)this->get_pointer() - (char*)other.get_pointer();   }
+
+   //!Returns true if both point to
+   //!the same object
+   bool equal(const self_t &y) const
+   {  return this->get_pointer() == y.get_pointer();  }
+
+   //!Returns true if *this is less than other.
+   //!This only works with two basic_intersegment_ptr pointing
+   //!to the same segment group. Otherwise undefined. Never throws
+   bool less(const self_t &y) const
+   {  return this->get_pointer() < y.get_pointer(); }
+
+   void swap(self_t &other)
+   {
+      void *ptr_this  = this->get_pointer();
+      void *ptr_other = other.get_pointer();
+      other.set_from_pointer(ptr_this);
+      this->set_from_pointer(ptr_other);
+   }
+
+   //!Sets the object internals to represent the
+   //!address pointed by ptr
+   void set_from_pointer(const void *ptr)
+   {
+      if(!ptr){
+         this->set_null();
+         return;
+      }
+
+      std::size_t mode = this->get_mode();
+      if(mode == is_in_stack){
+         members.direct.addr = (void*)ptr;
+         return;
+      }
+      if(mode == is_relative){
+         char *beg_addr = (char*)this->relative_calculate_begin_addr();
+         std::size_t seg_size = this->relative_size();
+         if(ptr >= beg_addr && ptr < (beg_addr + seg_size)){
+            members.relative.off = (char*)ptr - (char*)this;
+            return;
+         }
+      }
+      std::size_t ptr_offset;
+      std::size_t this_offset;
+      segment_info_t ptr_info;
+      segment_info_t this_info;
+      void *ptr_base;
+      void *this_base;
+      get_segment_info_and_offset(this, this_info, this_offset, this_base);
+   
+      if(!this_info.group){
+         this->set_mode(is_in_stack);
+         this->members.direct.addr = (void*)ptr;
+      }
+      else{
+         get_segment_info_and_offset(ptr, ptr_info, ptr_offset, ptr_base);      
+
+         if(ptr_info.group != this_info.group){
+            this->set_mode(is_pointee_outside);
+            this->members.direct.addr = (void*)ptr;
+         }
+         else if(ptr_info.id == this_info.id){
+            this->set_mode(is_relative);
+            members.relative.off = ((char*)ptr - (char*)this);
+            this->relative_set_begin_from_base(this_base);
+            std::size_t pow, frc;
+            std::size_t s = calculate_size(this_info.size, pow, frc);
+            assert(this_info.size == s);
+            this->members.relative.pow = pow;
+            this->members.relative.frc = frc;
+         }
+         else{
+            this->set_mode(is_segmented);
+            this->members.segmented.segment = ptr_info.id;
+            this->members.segmented.off     = ptr_offset;
+         }
+      }
+   }
+
+   //!Sets the object internals to represent the address pointed 
+   //!by another flat_map_intersegment
+   void set_from_other(const self_t &other)
+   {
+      this->set_from_pointer(other.get_pointer());
+   }
+
+   //!Increments internal
+   //!offset
+   void inc_offset(std::ptrdiff_t bytes)
+   {
+      this->set_from_pointer((char*)this->get_pointer()+bytes);
+   }
+
+   //!Decrements internal
+   //!offset
+   void dec_offset(std::ptrdiff_t bytes)
+   {
+      this->set_from_pointer((char*)this->get_pointer()-bytes);
+   }
+
+   //////////////////////////////////////
+   //////////////////////////////////////
+   //////////////////////////////////////
+
+   flat_map_intersegment()
+      :  intersegment_base()
+   {}
+
+   ~flat_map_intersegment()
+   {}
+
+   private:
+
+   class segment_group_t
+   {
+      struct segment_data
+      {
+         void *addr;
+         std::size_t size;
+      };
+      vector<segment_data> m_segments;
+      multi_segment_services &m_ms_services;
+      
+      public:
+      segment_group_t(multi_segment_services &ms_services)
+         :  m_ms_services(ms_services)
+      {}
+
+      void push_back(void *addr, std::size_t size)
+      {
+         segment_data d = { addr, size };
+         m_segments.push_back(d);
+      }
+
+      void pop_back()
+      {
+         assert(!m_segments.empty());
+         m_segments.erase(--m_segments.end());
+      }
+
+
+      void *address_of(std::size_t segment_id)
+      {
+         assert(segment_id < (std::size_t)m_segments.size());
+         return m_segments[segment_id].addr;
+      }
+
+      void clear_segments()
+      {  m_segments.clear();  }
+
+      std::size_t get_size() const
+      {  return m_segments.size();  }
+
+      multi_segment_services &get_multi_segment_services() const
+      {  return m_ms_services;   }
+
+      friend bool operator< (const segment_group_t&l, const segment_group_t &r)
+      {  return &l.m_ms_services < &r.m_ms_services;   }
+   };
+
+   struct segment_info_t
+   {
+      std::size_t size;
+      std::size_t id;
+      segment_group_t *group;
+      segment_info_t()
+         :  size(0), id(0), group(0)
+      {}
+   };
+
+   typedef set<segment_group_t>  segment_groups_t;
+
+   typedef boost::interprocess::flat_map
+      <const void * 
+      ,segment_info_t
+      ,std::less<const void *> >          ptr_to_segment_info_t;
+
+   struct mappings_t : Mutex
+   {
+      //!Mutex to preserve integrity in multi-threaded
+      //!enviroments
+      typedef Mutex        mutex_type;
+      //!Maps base addresses and segment information 
+      //!(size and segment group and id)*
+      
+      ptr_to_segment_info_t      m_ptr_to_segment_info;
+
+      ~mappings_t()
+      {
+         //Check that all mappings have been erased
+         assert(m_ptr_to_segment_info.empty());
+      }
+   };
+
+   //Static members
+   static mappings_t       s_map;
+   static segment_groups_t s_groups;
+   public:
+
+   typedef segment_group_t*      segment_group_id;
+
+   //!Returns the segment and offset
+   //!of an address
+   static void get_segment_info_and_offset(const void *ptr, segment_info_t &segment, std::size_t &offset, void *&base)
+   {
+      //------------------------------------------------------------------
+      boost::interprocess::scoped_lock<typename mappings_t::mutex_type> lock(s_map);
+      //------------------------------------------------------------------
+      base = 0;
+      if(s_map.m_ptr_to_segment_info.empty()){
+         segment = segment_info_t();
+         offset  = detail::char_ptr_cast(ptr) - detail::char_ptr_cast();
+         return;
+      }
+      //Find the first base address greater than ptr
+      typename ptr_to_segment_info_t::iterator it 
+         = s_map.m_ptr_to_segment_info.upper_bound(ptr);
+      if(it == s_map.m_ptr_to_segment_info.begin()){
+         segment = segment_info_t();
+         offset  = detail::char_ptr_cast(ptr) - detail::char_ptr_cast();
+      }
+      //Go to the previous one
+      --it;
+      char *      segment_base = detail::char_ptr_cast(it->first);
+      std::size_t segment_size = it->second.size;
+      
+      if(segment_base <= detail::char_ptr_cast(ptr) &&
+         (segment_base + segment_size) >= detail::char_ptr_cast(ptr)){
+         segment = it->second;
+         offset  = detail::char_ptr_cast(ptr) - segment_base;
+         base = segment_base;
+      }
+      else{
+         segment = segment_info_t();
+         offset  = detail::char_ptr_cast(ptr) - detail::char_ptr_cast();
+      }
+   }
+
+   //!Associates a segment defined by group/id with a base address and size.
+   //!Returns false if the group is not found or there is an error
+   static void insert_mapping(segment_group_id group_id, void *ptr, std::size_t size)
+   {
+      //------------------------------------------------------------------
+      boost::interprocess::scoped_lock<typename mappings_t::mutex_type> lock(s_map);
+      //------------------------------------------------------------------
+
+      typedef typename ptr_to_segment_info_t::value_type value_type;
+      typedef typename ptr_to_segment_info_t::iterator   iterator;
+      typedef std::pair<iterator, bool>                  it_b_t;
+
+      segment_info_t info;
+      info.group = group_id;
+      info.size  = size;
+      info.id    = group_id->get_size();
+
+      it_b_t ret = s_map.m_ptr_to_segment_info.insert(value_type(ptr, info));
+      assert(ret.second);
+
+      value_eraser<ptr_to_segment_info_t> v_eraser(s_map.m_ptr_to_segment_info, ret.first);
+      group_id->push_back(ptr, size);
+      v_eraser.release();
+   }
+
+   static bool erase_last_mapping(segment_group_id group_id)
+   {
+      //------------------------------------------------------------------
+      boost::interprocess::scoped_lock<typename mappings_t::mutex_type> lock(s_map);
+      //------------------------------------------------------------------
+      if(!group_id->get_size()){
+         return false;
+      }
+      else{
+         void *addr = group_id->address_of(group_id->get_size()-1);
+         group_id->pop_back();
+         std::size_t erased = s_map.m_ptr_to_segment_info.erase(addr);
+         assert(erased);
+         return true;
+      }
+   }
+
+   static segment_group_id new_segment_group(multi_segment_services *services)
+   {
+      {  //------------------------------------------------------------------
+         boost::interprocess::scoped_lock<typename mappings_t::mutex_type> lock(s_map);
+         //------------------------------------------------------------------
+         typedef typename segment_groups_t::iterator iterator;
+         std::pair<iterator, bool> ret =
+            s_groups.insert(segment_group_t(*services));
+         assert(ret.second);
+         return &*ret.first;
+      }      
+   }
+
+   static bool delete_group(segment_group_id id)
+   {
+      {  //------------------------------------------------------------------
+         boost::interprocess::scoped_lock<typename mappings_t::mutex_type> lock(s_map);
+         //------------------------------------------------------------------
+         bool success = 1u == s_groups.erase(segment_group_t(*id));
+         if(success){
+            typedef typename ptr_to_segment_info_t::iterator ptr_to_segment_info_it;
+            ptr_to_segment_info_it it(s_map.m_ptr_to_segment_info.begin());
+            while(it != s_map.m_ptr_to_segment_info.end()){
+               if(it->second.group == id){
+                  it = s_map.m_ptr_to_segment_info.erase(it);
+               }
+               else{
+                  ++it;
+               }
+            }
+         }
+         return success;
+      }      
+   }
+};
+
+//!Static map-segment_info associated with
+//!flat_map_intersegment<>
+template <class Mutex>
+typename flat_map_intersegment<Mutex>::mappings_t 
+   flat_map_intersegment<Mutex>::s_map;
+
+//!Static segment group container associated with
+//!flat_map_intersegment<>
+template <class Mutex>
+typename flat_map_intersegment<Mutex>::segment_groups_t 
+   flat_map_intersegment<Mutex>::s_groups;
+
+//!A smart pointer that can point to a pointee that resides in another memory 
+//!memory mapped or shared memory segment.
+template <class T>
+class intersegment_ptr : public flat_map_intersegment<interprocess_mutex>
+{
+   typedef flat_map_intersegment<interprocess_mutex> PT;
+   typedef intersegment_ptr<T>                  self_t;
+   typedef PT                                      base_t;
+
+   void unspecified_bool_type_func() const {}
+   typedef void (self_t::*unspecified_bool_type)() const;
+
+   public:
+   typedef T *                                     pointer;
+   typedef typename detail::add_reference<T>::type reference;
+   typedef T                                       value_type;
+   typedef std::ptrdiff_t                          difference_type;
+   typedef std::random_access_iterator_tag         iterator_category;
+
+   public:   //Public Functions
+
+   //!Constructor from raw pointer (allows "0" pointer conversion).
+   //!Never throws.
+   intersegment_ptr(pointer ptr = 0)
+   {  base_t::set_from_pointer(ptr);   }
+
+   //!Constructor from other pointer.
+   //!Never throws.
+   template <class U>
+   intersegment_ptr(U *ptr){  base_t::set_from_pointer(pointer(ptr)); }
+
+   //!Constructor from other intersegment_ptr
+   //!Never throws
+   intersegment_ptr(const intersegment_ptr& ptr) 
+   {  base_t::set_from_other(ptr);   }
+
+   //!Constructor from other intersegment_ptr. If pointers of pointee types are 
+   //!convertible, intersegment_ptrs will be convertibles. Never throws.
+   template<class T2>
+   intersegment_ptr(const intersegment_ptr<T2> &ptr) 
+   {  pointer p(ptr.get());   (void)p; base_t::set_from_other(ptr); }
+
+   //!Emulates static_cast operator.
+   //!Never throws.
+   template<class U>
+   intersegment_ptr(const intersegment_ptr<U> &r, detail::static_cast_tag)
+   {  base_t::set_from_pointer(static_cast<T*>(r.get())); }
+/*
+   {  
+      if(r.is_null()){
+         base_t::set_from_pointer(0);
+      }
+      else{
+         //Some dirty tricks to safe segment operations.
+         //Calculate pointer adjustment and adjust offset.
+         pointer ptr = reinterpret_cast<pointer>(this);
+         std::ptrdiff_t difference = detail::char_ptr_cast(static_cast<T*>(ptr)) -
+                                     detail::char_ptr_cast(ptr);
+         base_t::set_from_other(r);
+         base_t::inc_offset(difference*sizeof(T));
+      }
+   }*/
+
+   //!Emulates const_cast operator.
+   //!Never throws.
+   template<class U>
+   intersegment_ptr(const intersegment_ptr<U> &r, detail::const_cast_tag)
+   {  base_t::set_from_pointer(const_cast<T*>(r.get())); }
+
+   //!Emulates dynamic_cast operator.
+   //!Never throws.
+   template<class U>
+   intersegment_ptr(const intersegment_ptr<U> &r, detail::dynamic_cast_tag)
+   {  base_t::set_from_pointer(dynamic_cast<T*>(r.get())); }
+
+   //!Emulates reinterpret_cast operator.
+   //!Never throws.
+   template<class U>
+   intersegment_ptr(const intersegment_ptr<U> &r, detail::reinterpret_cast_tag)
+   {  base_t::set_from_pointer(reinterpret_cast<T*>(r.get())); }
+
+   //!Obtains raw pointer from offset.
+   //!Never throws.
+   pointer get()const
+   {  return (pointer)base_t::get_pointer();   }
+
+   //!Pointer-like -> operator. It can return 0 pointer.
+   //!Never throws.
+   pointer operator->() const           
+   {  return self_t::get(); }
+
+   //!Dereferencing operator, if it is a null intersegment_ptr behavior 
+   //!is undefined. Never throws.
+   reference operator* () const           
+   {  return *(self_t::get());   }
+
+   //!Indexing operator.
+   //!Never throws.
+   reference operator[](std::ptrdiff_t idx) const   
+   {  return self_t::get()[idx];  }
+
+   //!Assignment from pointer (saves extra conversion).
+   //!Never throws.
+   intersegment_ptr& operator= (pointer from)
+   {  base_t::set_from_pointer(from); return *this;  }
+
+   //!Assignment from other intersegment_ptr.
+   //!Never throws.
+   intersegment_ptr& operator= (const intersegment_ptr &ptr)
+   {  base_t::set_from_other(ptr);  return *this;  }
+
+   //!Assignment from related intersegment_ptr. If pointers of pointee types 
+   //!are assignable, intersegment_ptrs will be assignable. Never throws.
+   template <class T2>
+   intersegment_ptr& operator= (const intersegment_ptr<T2> & ptr)
+   {  
+      pointer p(ptr.get());   (void)p; 
+      base_t::set_from_other(ptr); return *this;   
+   }
+ 
+   //!intersegment_ptr + std::ptrdiff_t.
+   //!Never throws.
+   intersegment_ptr operator+ (std::ptrdiff_t idx) const   
+   {  
+      intersegment_ptr result (*this);
+      result.inc_offset(idx*sizeof(T));
+      return result;
+   }
+
+   //!intersegment_ptr - std::ptrdiff_t.
+   //!Never throws.
+   intersegment_ptr operator- (std::ptrdiff_t idx) const   
+   {  
+      intersegment_ptr result (*this);
+      result.dec_offset(idx*sizeof(T));
+      return result;
+   }
+
+   //!intersegment_ptr += std::ptrdiff_t.
+   //!Never throws.
+   intersegment_ptr &operator+= (std::ptrdiff_t offset)
+   {  base_t::inc_offset(offset*sizeof(T));  return *this;  }
+
+   //!intersegment_ptr -= std::ptrdiff_t.
+   //!Never throws.
+   intersegment_ptr &operator-= (std::ptrdiff_t offset)
+   {  base_t::dec_offset(offset*sizeof(T));  return *this;  }
+
+   //!++intersegment_ptr.
+   //!Never throws.
+   intersegment_ptr& operator++ (void)
+   {  base_t::inc_offset(sizeof(T));   return *this;  }
+ 
+   //!intersegment_ptr++.
+   //!Never throws.
+   intersegment_ptr operator++ (int)
+   {  intersegment_ptr temp(*this); ++*this; return temp; }
+
+   //!--intersegment_ptr.
+   //!Never throws.
+   intersegment_ptr& operator-- (void)
+   {  base_t::dec_offset(sizeof(T));   return *this;  }
+
+   //!intersegment_ptr--.
+   //!Never throws.
+   intersegment_ptr operator-- (int)
+   {  intersegment_ptr temp(*this); --*this; return temp; }
+
+   //!Safe bool conversion operator.
+   //!Never throws.
+   operator unspecified_bool_type() const  
+   {  return base_t::is_null()? 0 : &self_t::unspecified_bool_type_func;   }
+
+   //!Not operator. Not needed in theory, but improves portability. 
+   //!Never throws.
+   bool operator! () const
+   {  return base_t::is_null();   }
+
+   //!Swaps two intersegment_ptr-s. More efficient than std::swap.
+   //!Never throws.
+   void swap(intersegment_ptr &other)
+   {  base_t::swap(other);   }
+
+   //!Calculates the distance between two intersegment_ptr-s.
+   //!This only works with two basic_intersegment_ptr pointing
+   //!to the same segment. Otherwise undefined
+   template <class T2>
+   ptrdiff_t _diff(const intersegment_ptr<T2> &other) const
+   {  return base_t::diff(other);   }
+
+   //!Returns true if both point to the
+   //!same object
+   template <class T2>
+   bool _equal(const intersegment_ptr<T2>&other) const
+   {  return base_t::equal(other);   }
+
+   //!Returns true if *this is less than other.
+   //!This only works with two basic_intersegment_ptr pointing
+   //!to the same segment group. Otherwise undefined. Never throws
+   template <class T2>
+   bool _less(const intersegment_ptr<T2> &other) const
+   {  return base_t::less(other);   }
+};
+
+//!Compares the equality of two intersegment_ptr-s.
+//!Never throws.
+template <class T1, class T2> inline
+bool operator ==(const intersegment_ptr<T1> &left,
+                 const intersegment_ptr<T2> &right)
+{  
+   //Make sure both pointers can be compared
+   bool e = typename intersegment_ptr<T1>::pointer(0) ==
+            typename intersegment_ptr<T2>::pointer(0);
+   (void)e;
+   return left._equal(right);   
+}
+
+//!Returns true if *this is less than other.
+//!This only works with two basic_intersegment_ptr pointing
+//!to the same segment group. Otherwise undefined. Never throws
+template <class T1, class T2> inline
+bool operator <(const intersegment_ptr<T1> &left,
+                const intersegment_ptr<T2> &right)
+{  
+   //Make sure both pointers can be compared
+   bool e = typename intersegment_ptr<T1>::pointer(0) <
+            typename intersegment_ptr<T2>::pointer(0);
+   (void)e;
+   return left._less(right);   
+}
+
+template<class T1, class T2> inline
+bool operator!= (const intersegment_ptr<T1> &pt1, 
+                 const intersegment_ptr<T2> &pt2)
+{  return !(pt1 ==pt2);  }
+
+//!intersegment_ptr<T1> <= intersegment_ptr<T2>.
+//!Never throws.
+template<class T1, class T2> inline
+bool operator<= (const intersegment_ptr<T1> &pt1, 
+                 const intersegment_ptr<T2> &pt2)
+{  return !(pt1 > pt2);  }
+
+//!intersegment_ptr<T1> > intersegment_ptr<T2>.
+//!Never throws.
+template<class T1, class T2> inline
+bool operator> (const intersegment_ptr<T1> &pt1, 
+                       const intersegment_ptr<T2> &pt2)
+{  return (pt2 < pt1);  }
+
+//!intersegment_ptr<T1> >= intersegment_ptr<T2>.
+//!Never throws.
+template<class T1, class T2> inline
+bool operator>= (const intersegment_ptr<T1> &pt1, 
+                 const intersegment_ptr<T2> &pt2)
+{  return !(pt1 < pt2);  }
+
+//!operator<<
+template<class E, class T, class U> inline
+std::basic_ostream<E, T> & operator<< 
+   (std::basic_ostream<E, T> & os, const intersegment_ptr<U> & p)
+{  return os << p.get();   }
+
+//!operator>>
+template<class E, class T, class U> inline
+std::basic_istream<E, T> & operator>> 
+   (std::basic_istream<E, T> & os, intersegment_ptr<U> & p)
+{  U * tmp; return os >> tmp; p = tmp;   }
+
+//!std::ptrdiff_t + intersegment_ptr. 
+//!The result is another pointer of the same segment
+template<class T> inline
+intersegment_ptr<T> operator+
+   (std::ptrdiff_t diff, const intersegment_ptr<T>& right)
+{  return right + diff;  }
+
+//!intersegment_ptr - intersegment_ptr. 
+//!This only works with two intersegment_ptr-s that point to the
+//!same segment
+template <class T, class T2> inline
+std::ptrdiff_t operator- (const intersegment_ptr<T> &pt, 
+                          const intersegment_ptr<T2> &pt2)
+{  return pt._diff(pt2)/sizeof(T);  }
+
+//! swap specialization
+template<class T> inline
+void swap (boost::interprocess::intersegment_ptr<T> &pt, 
+           boost::interprocess::intersegment_ptr<T> &pt2)
+{  pt.swap(pt2);  }
+
+//!get_pointer() enables boost::mem_fn to recognize intersegment_ptr. 
+//!Never throws.
+template<class T> inline
+T * get_pointer(boost::interprocess::intersegment_ptr<T> const & p)
+{  return p.get();   }
+
+//!Simulation of static_cast between pointers.
+//!Never throws.
+template<class T, class U> inline 
+boost::interprocess::intersegment_ptr<T> static_pointer_cast(const boost::interprocess::intersegment_ptr<U> &r)
+{  return boost::interprocess::intersegment_ptr<T>(r, boost::interprocess::detail::static_cast_tag());  }
+
+//!Simulation of const_cast between pointers.
+//!Never throws.
+template<class T, class U> inline 
+boost::interprocess::intersegment_ptr<T> const_pointer_cast(const boost::interprocess::intersegment_ptr<U> &r)
+{  return boost::interprocess::intersegment_ptr<T>(r, boost::interprocess::detail::const_cast_tag());  }
+
+//!Simulation of dynamic_cast between pointers.
+//!Never throws.
+template<class T, class U> inline 
+boost::interprocess::intersegment_ptr<T> dynamic_pointer_cast(const boost::interprocess::intersegment_ptr<U> &r)
+{  return boost::interprocess::intersegment_ptr<T>(r, boost::interprocess::detail::dynamic_cast_tag());  }
+
+//!Simulation of reinterpret_cast between pointers.
+//!Never throws.
+template<class T, class U> inline
+boost::interprocess::intersegment_ptr<T> reinterpret_pointer_cast(const boost::interprocess::intersegment_ptr<U> &r)
+{  return boost::interprocess::intersegment_ptr<T>(r, boost::interprocess::detail::reinterpret_cast_tag());  }
+
+//!Trait class to detect if an smart pointer has 
+//!multi-segment addressing capabilities.
+template <class T>
+struct is_multisegment_ptr
+   <boost::interprocess::intersegment_ptr<T> >
+{
+   static const bool value = true;
+};
+
+}  //namespace interprocess {
+
+#if defined(_MSC_VER) && (_MSC_VER < 1400)
+//!get_pointer() enables boost::mem_fn to recognize intersegment_ptr. 
+//!Never throws.
+template<class T> inline
+T * get_pointer(boost::interprocess::intersegment_ptr<T> const & p)
+{  return p.get();   }
+#endif
+
+//!has_trivial_constructor<> == true_type specialization
+//!for optimizations
+template <class T>
+struct has_trivial_constructor
+   < boost::interprocess::intersegment_ptr<T> > 
+   : public true_type{};
+
+//!has_trivial_destructor<> == true_type specialization
+//!for optimizations
+template <class T>
+struct has_trivial_destructor
+   < boost::interprocess::intersegment_ptr<T> > 
+   : public true_type{};
+
+}  //namespace boost {
+
+#include <boost/interprocess/detail/config_end.hpp>
+
+#if 0
+
+//bits
+//-> is_segmented
+//-> is_relative
+//-> is_in_stack
+//-> is_pointee_outside
+
+//Data
+
+
+
+
+//segmented:
+//
+// std::size_t ctrl    : CTRL_BITS;
+// std::size_t segment : MAX_SEGMENT_BITS;
+// std::size_t offset;
+
+//RELATIVE_SIZE_BITS =  SIZE_T_BITS -
+//                      MAX_SEGMENT_BITS - 
+//                      CTRL_BITS                  10    10
+//MAX_SEGMENT_SIZE   = SIZE_T_BITS - ALIGN_BITS    20    52
+
+//SIZE_T_BITS - 1 - ALIGN_BITS                     19    51
+//POW_SIZE_BITS = upper_log2
+// (SIZE_T_BITS - 1 - ALIGN_BITS)                  5     6
+//FRC_SIZE_BITS = SIZE_T_BITS - CTRL_BITS
+//  MAX_SEGMENT_SIZE_ALIGNBITS - POW_SIZE_BITS     6     5
+
+//relative:
+//
+// std::size_t ctrl     : CTRL_BITS;               2     2
+// std::size_t size_pow : POW_SIZE_BITS            5     6
+// std::size_t size_frc : FRC_SIZE_BITS;           6     5
+// std::size_t start    : MAX_SEGMENT_SIZE_ALIGNBITS;19    51
+// std::ptrdiff_t distance : SIZE_T_BITS;          32    64
+
+//direct:
+//
+// std::size_t ctrl     : CTRL_BITS;               2     2
+// std::size_t dummy    : SIZE_T_BITS - CTRL_BITS  30    62
+// void *addr           : SIZE_T_BITS;             32    64
+
+//32 bits systems:
+//Page alignment: 2**12
+//
+
+//!Obtains the address pointed by the
+//!object
+void *get_pointer() const
+{
+   if(this->is_pointee_outside() || this->is_in_stack()){
+      return raw_address();
+   }
+   else if(this->is_relative()){
+      return ((char*)this) + this->relative_pointee_offset();
+   }
+   else{
+      group_manager *m     = get_segment_group_manager(addr);
+      char *base  = (char*)m->get_id_address(this->segmented_id());
+      return base + this->segmented_offset();
+   }
+}
+
+void set_from_pointer(const void *ptr)
+{
+   if(!ptr){
+      this->set_pointee_outside();
+      this->raw_address(ptr);
+   }
+   else if(this->is_in_stack()){
+      this->raw_address(ptr);
+   }
+   else if(this->is_relative() &&
+            (  (ptr >= this->relative_start())
+            &&(ptr <  this->relative_start() + this->relative_size()))
+            ){
+      this->relative_offset(ptr - this);
+   }
+   else{
+      segment_info_t ptr_info  = get_id_from_addr(ptr);
+      segment_info_t this_info = get_id_from_addr(this);
+      if(ptr_info.segment_group != this_info.segment_group){
+         if(!ptr_info.segment_group){
+            this->set_in_stack();
+         }
+         else{
+            this->set_pointee_outside();
+         }
+      }
+      else if(ptr_info.segment_id == this_info.segment_id){
+         set_relative();
+         this->relative_size  (ptr_info.size);
+         this->relative_offset((char*)ptr - (char*)this);
+         this->relative_start (ptr_info.base);
+      }
+   }
+}
+
+void set_from_other(const self_t &other)
+{  this->set_from_pointer(other.get_pointer()); }
+
+#endif
+
+#endif //#ifndef BOOST_INTERPROCESS_INTERSEGMENT_PTR_HPP
+