flat_map.hpp

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//////////////////////////////////////////////////////////////////////////////
//
// (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_FLAT_MAP_HPP
#define BOOST_INTERPROCESS_FLAT_MAP_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 <utility>
#include <functional>
#include <memory>
#include <boost/interprocess/containers/detail/flat_tree.hpp>
#include <boost/interprocess/detail/utilities.hpp>
#include <boost/type_traits/has_trivial_destructor.hpp>
#include <boost/interprocess/detail/mpl.hpp>
#include <boost/interprocess/detail/move.hpp>

namespace boost { namespace interprocess {

/// @cond
// Forward declarations of operators == and <, needed for friend declarations.
template <class Key, class T, class Pred, class Alloc>
class flat_map;

template <class Key, class T, class Pred, class Alloc>
inline bool operator==(const flat_map<Key,T,Pred,Alloc>& x, 
                       const flat_map<Key,T,Pred,Alloc>& y);

template <class Key, class T, class Pred, class Alloc>
inline bool operator<(const flat_map<Key,T,Pred,Alloc>& x, 
                      const flat_map<Key,T,Pred,Alloc>& y);
/// @endcond

//! A flat_map is a kind of associative container that supports unique keys (contains at
//! most one of each key value) and provides for fast retrieval of values of another 
//! type T based on the keys. The flat_map class supports random-access iterators.
//! 
//! A flat_map satisfies all of the requirements of a container and of a reversible 
//! container and of an associative container. A flat_map also provides 
//! most operations described for unique keys. For a 
//! flat_map<Key,T> the key_type is Key and the value_type is std::pair<Key,T>
//! (unlike std::map<Key, T> which value_type is std::pair<<b>const</b> Key, T>).
//!
//! Pred is the ordering function for Keys (e.g. <i>std::less<Key></i>).
//!
//! Alloc is the allocator to allocate the value_types
//! (e.g. <i>boost::interprocess:allocator< std::pair<Key, T></i>).
//! 
//! flat_map is similar to std::map but it's implemented like an ordered vector.
//! This means that inserting a new element into a flat_map invalidates
//! previous iterators and references
//!
//! Erasing an element of a flat_map invalidates iterators and references 
//! pointing to elements that come after (their keys are bigger) the erased element.
template <class Key, class T, class Pred, class Alloc>
class flat_map 
{
   /// @cond
   private:
   //This is the tree that we should store if pair was movable
   typedef detail::flat_tree<Key, 
                           std::pair<Key, T>, 
                           detail::select1st< std::pair<Key, T> >, 
                           Pred, 
                           Alloc> tree_t;

   //#ifndef BOOST_INTERPROCESS_RVALUE_REFERENCE
   //This is the real tree stored here. It's based on a movable pair
   typedef detail::flat_tree<Key, 
                           detail::pair<Key, T>, 
                           detail::select1st< detail::pair<Key, T> >, 
                           Pred, 
                           typename Alloc::template
                              rebind<detail::pair<Key, T> >::other> impl_tree_t;
/*
   #else
   typedef tree_t    impl_tree_t;
   #endif   
*/
   impl_tree_t m_flat_tree;  // flat tree representing flat_map

   typedef typename impl_tree_t::value_type             impl_value_type;
   typedef typename impl_tree_t::pointer                impl_pointer;
   typedef typename impl_tree_t::const_pointer          impl_const_pointer;
   typedef typename impl_tree_t::reference              impl_reference;
   typedef typename impl_tree_t::const_reference        impl_const_reference;
   typedef typename impl_tree_t::value_compare          impl_value_compare;
   typedef typename impl_tree_t::iterator               impl_iterator;
   typedef typename impl_tree_t::const_iterator         impl_const_iterator;
   typedef typename impl_tree_t::reverse_iterator       impl_reverse_iterator;
   typedef typename impl_tree_t::const_reverse_iterator impl_const_reverse_iterator;
   typedef typename impl_tree_t::allocator_type         impl_allocator_type;
   #ifndef BOOST_INTERPROCESS_RVALUE_REFERENCE
   typedef detail::moved_object<impl_value_type>        impl_moved_value_type;
   #endif

   //#ifndef BOOST_INTERPROCESS_RVALUE_REFERENCE
   template<class D, class S>
   static D &force(const S &s)
   {  return *const_cast<D*>(reinterpret_cast<const D*>(&s)); }

   template<class D, class S>
   static D force_copy(S s)
   {
      value_type *vp = reinterpret_cast<value_type *>(&*s);
      return D(vp);
   }

   /// @endcond

   public:
   // typedefs:
   typedef typename tree_t::key_type               key_type;
   typedef typename tree_t::value_type             value_type;
   typedef typename tree_t::pointer                pointer;
   typedef typename tree_t::const_pointer          const_pointer;
   typedef typename tree_t::reference              reference;
   typedef typename tree_t::const_reference        const_reference;
   typedef typename tree_t::value_compare          value_compare;
   typedef T                                       mapped_type;
   typedef typename tree_t::key_compare            key_compare;
   typedef typename tree_t::iterator               iterator;
   typedef typename tree_t::const_iterator         const_iterator;
   typedef typename tree_t::reverse_iterator       reverse_iterator;
   typedef typename tree_t::const_reverse_iterator const_reverse_iterator;
   typedef typename tree_t::size_type              size_type;
   typedef typename tree_t::difference_type        difference_type;
   typedef typename tree_t::allocator_type         allocator_type;
   typedef typename tree_t::stored_allocator_type  stored_allocator_type;

   //! <b>Effects</b>: Constructs an empty flat_map using the specified
   //! comparison object and allocator.
   //! 
   //! <b>Complexity</b>: Constant.
   explicit flat_map(const Pred& comp = Pred(), const allocator_type& a = allocator_type()) 
      : m_flat_tree(comp, force<impl_allocator_type>(a)) {}

   //! <b>Effects</b>: Constructs an empty flat_map using the specified comparison object and 
   //! allocator, and inserts elements from the range [first ,last ).
   //! 
   //! <b>Complexity</b>: Linear in N if the range [first ,last ) is already sorted using 
   //! comp and otherwise N logN, where N is last - first.
   template <class InputIterator>
   flat_map(InputIterator first, InputIterator last, const Pred& comp = Pred(),
         const allocator_type& a = allocator_type())
      : m_flat_tree(comp, force<impl_allocator_type>(a)) 
      { m_flat_tree.insert_unique(first, last); }

   //! <b>Effects</b>: Copy constructs a flat_map.
   //! 
   //! <b>Complexity</b>: Linear in x.size().
   flat_map(const flat_map<Key,T,Pred,Alloc>& x) 
      : m_flat_tree(x.m_flat_tree) {}

   //! <b>Effects</b>: Move constructs a flat_map.
   //!   Constructs *this using x's resources.
   //! 
   //! <b>Complexity</b>: Construct.
   //! 
   //! <b>Postcondition</b>: x is emptied.
   #ifndef BOOST_INTERPROCESS_RVALUE_REFERENCE
   flat_map(const detail::moved_object<flat_map<Key,T,Pred,Alloc> >& x) 
      : m_flat_tree(detail::move_impl(x.get().m_flat_tree)) {}

   #else
   flat_map(flat_map<Key,T,Pred,Alloc> && x) 
      : m_flat_tree(detail::move_impl(x.m_flat_tree)) {}
   #endif

   //! <b>Effects</b>: Makes *this a copy of x.
   //! 
   //! <b>Complexity</b>: Linear in x.size().
   flat_map<Key,T,Pred,Alloc>& operator=(const flat_map<Key, T, Pred, Alloc>& x)
      {  m_flat_tree = x.m_flat_tree;   return *this;  }

   //! <b>Effects</b>: Move constructs a flat_map.
   //!   Constructs *this using x's resources.
   //! 
   //! <b>Complexity</b>: Construct.
   //! 
   //! <b>Postcondition</b>: x is emptied.
   #ifndef BOOST_INTERPROCESS_RVALUE_REFERENCE
   flat_map<Key,T,Pred,Alloc>& operator=(const detail::moved_object<flat_map<Key, T, Pred, Alloc> >& mx)
      {  m_flat_tree = detail::move_impl(mx.get().m_flat_tree);   return *this;  }
   #else
   flat_map<Key,T,Pred,Alloc>& operator=(flat_map<Key, T, Pred, Alloc> && mx)
      {  m_flat_tree = detail::move_impl(mx.m_flat_tree);   return *this;  }
   #endif

   //! <b>Effects</b>: Returns the comparison object out
   //!   of which a was constructed.
   //! 
   //! <b>Complexity</b>: Constant.
   key_compare key_comp() const 
      { return force<key_compare>(m_flat_tree.key_comp()); }

   //! <b>Effects</b>: Returns an object of value_compare constructed out
   //!   of the comparison object.
   //! 
   //! <b>Complexity</b>: Constant.
   value_compare value_comp() const 
      { return value_compare(force<key_compare>(m_flat_tree.key_comp())); }

   //! <b>Effects</b>: Returns a copy of the Allocator that
   //!   was passed to the object's constructor.
   //! 
   //! <b>Complexity</b>: Constant.
   allocator_type get_allocator() const 
      { return force<allocator_type>(m_flat_tree.get_allocator()); }

   const stored_allocator_type &get_stored_allocator() const 
      { return force<stored_allocator_type>(m_flat_tree.get_stored_allocator()); }

   stored_allocator_type &get_stored_allocator()
      { return force<stored_allocator_type>(m_flat_tree.get_stored_allocator()); }

   //! <b>Effects</b>: Returns an iterator to the first element contained in the container.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   iterator begin() 
      { return force_copy<iterator>(m_flat_tree.begin()); }

   //! <b>Effects</b>: Returns a const_iterator to the first element contained in the container.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_iterator begin() const 
      { return force<const_iterator>(m_flat_tree.begin()); }

   //! <b>Effects</b>: Returns a const_iterator to the first element contained in the container.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_iterator cbegin() const 
      { return force<const_iterator>(m_flat_tree.cbegin()); }

   //! <b>Effects</b>: Returns an iterator to the end of the container.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   iterator end() 
      { return force_copy<iterator>(m_flat_tree.end()); }

   //! <b>Effects</b>: Returns a const_iterator to the end of the container.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_iterator end() const 
      { return force<const_iterator>(m_flat_tree.end()); }

   //! <b>Effects</b>: Returns a const_iterator to the end of the container.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_iterator cend() const 
      { return force<const_iterator>(m_flat_tree.cend()); }

   //! <b>Effects</b>: Returns a reverse_iterator pointing to the beginning 
   //! of the reversed container. 
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   reverse_iterator rbegin() 
      { return force<reverse_iterator>(m_flat_tree.rbegin()); }

   //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the beginning 
   //! of the reversed container. 
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_reverse_iterator rbegin() const 
      { return force<const_reverse_iterator>(m_flat_tree.rbegin()); }

   //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the beginning 
   //! of the reversed container. 
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_reverse_iterator crbegin() const 
      { return force<const_reverse_iterator>(m_flat_tree.crbegin()); }

   //! <b>Effects</b>: Returns a reverse_iterator pointing to the end
   //! of the reversed container. 
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   reverse_iterator rend() 
      { return force<reverse_iterator>(m_flat_tree.rend()); }

   //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the end
   //! of the reversed container. 
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_reverse_iterator rend() const 
      { return force<const_reverse_iterator>(m_flat_tree.rend()); }

   //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the end
   //! of the reversed container. 
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_reverse_iterator crend() const 
      { return force<const_reverse_iterator>(m_flat_tree.crend()); }

   //! <b>Effects</b>: Returns true if the container contains no elements.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   bool empty() const 
      { return m_flat_tree.empty(); }

   //! <b>Effects</b>: Returns the number of the elements contained in the container.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   size_type size() const 
      { return m_flat_tree.size(); }

   //! <b>Effects</b>: Returns the largest possible size of the container.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   size_type max_size() const 
      { return m_flat_tree.max_size(); }

   //! Effects: If there is no key equivalent to x in the flat_map, inserts 
   //! value_type(detail::move_impl(x), T()) into the flat_map (the key is move-constructed)
   //! 
   //! Returns: A reference to the mapped_type corresponding to x in *this.
   //! 
   //! Complexity: Logarithmic.