code:
//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2005-2013. 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/container for documentation.
//
//////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_CONTAINER_MAP_HPP
#define BOOST_CONTAINER_MAP_HPP

#ifndef BOOST_CONFIG_HPP
#  include <boost/config.hpp>
#endif

#if defined(BOOST_HAS_PRAGMA_ONCE)
#  pragma once
#endif

#include <boost/container/detail/config_begin.hpp>
#include <boost/container/detail/workaround.hpp>

// container
#include <boost/container/container_fwd.hpp>
#include <boost/container/new_allocator.hpp> //new_allocator
#include <boost/container/throw_exception.hpp>
// container/detail
#include <boost/container/detail/mpl.hpp>
#include <boost/container/detail/tree.hpp>
#include <boost/container/detail/type_traits.hpp>
#include <boost/container/detail/value_init.hpp>
#include <boost/container/detail/pair.hpp>
// move
#include <boost/move/traits.hpp>
#include <boost/move/utility_core.hpp>
// move/detail
#if defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
#include <boost/move/detail/fwd_macros.hpp>
#endif
#include <boost/move/detail/move_helpers.hpp>
// intrusive/detail
#include <boost/intrusive/detail/minimal_pair_header.hpp>      //pair
#include <boost/intrusive/detail/minimal_less_equal_header.hpp>//less, equal
// other
#include <boost/static_assert.hpp>
#include <boost/core/no_exceptions_support.hpp>
// std
#if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
#include <initializer_list>
#endif

namespace boost {
namespace container {

///@cond

template<class Key, class Mapped>
struct pair_key_mapped_of_value
{
   typedef Key    key_type;
   typedef Mapped mapped_type;

   template<class Pair>
   const key_type & key_of_value(const Pair &p) const
   {  return p.first;  }

   template<class Pair>
   const mapped_type & mapped_of_value(const Pair &p) const
   {  return p.second;  }

   template<class Pair>
   key_type & key_of_value(Pair &p) const
   {  return const_cast<key_type&>(p.first);  }

   template<class Pair>
   mapped_type & mapped_of_value(Pair &p) const
   {  return p.second;  }

};

///@endcond

#ifdef BOOST_CONTAINER_DOXYGEN_INVOKED

//! A 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 map class supports bidirectional iterators.
//!
//! A map satisfies all of the requirements of a container and of a reversible
//! container and of an associative container. The value_type stored
//! by this container is the value_type is std::pair<const Key, T>.
//!
//! \tparam Key is the key_type of the map
//! \tparam T is the mapped_type
//! \tparam Compare is the ordering function for Keys (e.g. std::less<Key>).
//! \tparam Allocator is the allocator to allocate the value_types
//!   (e.g. allocator< std::pair<const Key, T> > ).
//! \tparam Options is an packed option type generated using using boost::container::tree_assoc_options.
template < class Key, class T, class Compare = std::less<Key>
         , class Allocator = new_allocator< std::pair< const Key, T> >, class Options = tree_assoc_defaults >
#else
template <class Key, class T, class Compare, class Allocator, class Options>
#endif
class map
   ///@cond
   : public container_detail::tree
      < std::pair<const Key, T>
      , container_detail::select1st<Key>
      , Compare, Allocator, Options>
   ///@endcond
{
   #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
   private:
   BOOST_COPYABLE_AND_MOVABLE(map)

   typedef container_detail::select1st<Key>                                select_1st_t;
   typedef std::pair<const Key, T>                                         value_type_impl;
   typedef container_detail::tree
      <value_type_impl, select_1st_t, Compare, Allocator, Options>         base_t;
   typedef container_detail::pair <Key, T>                                 movable_value_type_impl;
   typedef typename base_t::value_compare                                  value_compare_impl;
   #endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED

   public:
   //////////////////////////////////////////////
   //
   //                    types
   //
   //////////////////////////////////////////////

   typedef Key                                                                      key_type;
   typedef ::boost::container::allocator_traits<Allocator>                          allocator_traits_type;
   typedef T                                                                        mapped_type;
   typedef std::pair<const Key, T>                                                  value_type;
   typedef typename boost::container::allocator_traits<Allocator>::pointer          pointer;
   typedef typename boost::container::allocator_traits<Allocator>::const_pointer    const_pointer;
   typedef typename boost::container::allocator_traits<Allocator>::reference        reference;
   typedef typename boost::container::allocator_traits<Allocator>::const_reference  const_reference;
   typedef typename boost::container::allocator_traits<Allocator>::size_type        size_type;
   typedef typename boost::container::allocator_traits<Allocator>::difference_type  difference_type;
   typedef Allocator                                                                allocator_type;
   typedef typename BOOST_CONTAINER_IMPDEF(base_t::stored_allocator_type)           stored_allocator_type;
   typedef BOOST_CONTAINER_IMPDEF(value_compare_impl)                               value_compare;
   typedef Compare                                                                  key_compare;
   typedef typename BOOST_CONTAINER_IMPDEF(base_t::iterator)                        iterator;
   typedef typename BOOST_CONTAINER_IMPDEF(base_t::const_iterator)                  const_iterator;
   typedef typename BOOST_CONTAINER_IMPDEF(base_t::reverse_iterator)                reverse_iterator;
   typedef typename BOOST_CONTAINER_IMPDEF(base_t::const_reverse_iterator)          const_reverse_iterator;
   typedef std::pair<key_type, mapped_type>                                         nonconst_value_type;
   typedef BOOST_CONTAINER_IMPDEF(movable_value_type_impl)                          movable_value_type;
   typedef BOOST_CONTAINER_IMPDEF(node_handle<
      typename base_t::node_type::container_node_type
      BOOST_MOVE_I value_type
      BOOST_MOVE_I allocator_type
      BOOST_MOVE_I pair_key_mapped_of_value
         <key_type BOOST_MOVE_I mapped_type> >)                                     node_type;
   typedef BOOST_CONTAINER_IMPDEF
      (insert_return_type_base<iterator BOOST_MOVE_I node_type>)                    insert_return_type;

   //////////////////////////////////////////////
   //
   //          construct/copy/destroy
   //
   //////////////////////////////////////////////

   //! Effects: Default constructs an empty map.
   //!
   //! Complexity: Constant.
   BOOST_CONTAINER_FORCEINLINE
   map() BOOST_NOEXCEPT_IF(container_detail::is_nothrow_default_constructible<Allocator>::value &&
                           container_detail::is_nothrow_default_constructible<Compare>::value)
      : base_t()
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty map using the specified comparison object
   //! and allocator.
   //!
   //! Complexity: Constant.
   BOOST_CONTAINER_FORCEINLINE
   explicit map(const Compare& comp, const allocator_type& a = allocator_type())
      : base_t(comp, a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty map using the specified allocator.
   //!
   //! Complexity: Constant.
   BOOST_CONTAINER_FORCEINLINE
   explicit map(const allocator_type& a)
      : base_t(a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty map using the specified comparison object and
   //! allocator, and inserts elements from the range [first ,last ).
   //!
   //! Complexity: 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>
   BOOST_CONTAINER_FORCEINLINE
   map(InputIterator first, InputIterator last, const Compare& comp = Compare(),
         const allocator_type& a = allocator_type())
      : base_t(true, first, last, comp, a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty map using the specified
   //! allocator, and inserts elements from the range [first ,last ).
   //!
   //! Complexity: 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>
   BOOST_CONTAINER_FORCEINLINE
   map(InputIterator first, InputIterator last, const allocator_type& a)
      : base_t(true, first, last, Compare(), a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty map using the specified comparison object and
   //! allocator, and inserts elements from the ordered unique range [first ,last). This function
   //! is more efficient than the normal range creation for ordered ranges.
   //!
   //! Requires: [first ,last) must be ordered according to the predicate and must be
   //! unique values.
   //!
   //! Complexity: Linear in N.
   //!
   //! Note: Non-standard extension.
   template <class InputIterator>
   BOOST_CONTAINER_FORCEINLINE
   map( ordered_unique_range_t, InputIterator first, InputIterator last
      , const Compare& comp = Compare(), const allocator_type& a = allocator_type())
      : base_t(ordered_range, first, last, comp, a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

#if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
   //! Effects: Constructs an empty map using the specified comparison object and
   //! allocator, and inserts elements from the range [il.begin(), il.end()).
   //!
   //! Complexity: Linear in N if the range [first ,last ) is already sorted using
   //! comp and otherwise N logN, where N is il.first() - il.end().
   BOOST_CONTAINER_FORCEINLINE
   map(std::initializer_list<value_type> il, const Compare& comp = Compare(), const allocator_type& a = allocator_type())
      : base_t(true, il.begin(), il.end(), comp, a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty map using the specified
   //! allocator, and inserts elements from the range [il.begin(), il.end()).
   //!
   //! Complexity: Linear in N if the range [first ,last ) is already sorted using
   //! comp and otherwise N logN, where N is il.first() - il.end().
   BOOST_CONTAINER_FORCEINLINE
   map(std::initializer_list<value_type> il, const allocator_type& a)
      : base_t(true, il.begin(), il.end(), Compare(), a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty set using the specified comparison object and
   //! allocator, and inserts elements from the ordered unique range [il.begin(), il.end()). This function
   //! is more efficient than the normal range creation for ordered ranges.
   //!
   //! Requires: [il.begin(), il.end()) must be ordered according to the predicate and must be
   //! unique values.
   //!
   //! Complexity: Linear in N.
   //!
   //! Note: Non-standard extension.
   BOOST_CONTAINER_FORCEINLINE
   map(ordered_unique_range_t, std::initializer_list<value_type> il, const Compare& comp = Compare(),
       const allocator_type& a = allocator_type())
      : base_t(ordered_range, il.begin(), il.end(), comp, a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }
#endif

   //! Effects: Copy constructs a map.
   //!
   //! Complexity: Linear in x.size().
   BOOST_CONTAINER_FORCEINLINE
   map(const map& x)
      : base_t(static_cast<const base_t&>(x))
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Move constructs a map. Constructs *this using x's resources.
   //!
   //! Complexity: Constant.
   //!
   //! Postcondition: x is emptied.
   BOOST_CONTAINER_FORCEINLINE
   map(BOOST_RV_REF(map) x)
      BOOST_NOEXCEPT_IF(boost::container::container_detail::is_nothrow_move_constructible<Compare>::value)
      : base_t(BOOST_MOVE_BASE(base_t, x))
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Copy constructs a map using the specified allocator.
   //!
   //! Complexity: Linear in x.size().
   BOOST_CONTAINER_FORCEINLINE
   map(const map& x, const allocator_type &a)
      : base_t(static_cast<const base_t&>(x), a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Move constructs a map using the specified allocator.
   //!                 Constructs *this using x's resources.
   //!
   //! Complexity: Constant if x == x.get_allocator(), linear otherwise.
   //!
   //! Postcondition: x is emptied.
   BOOST_CONTAINER_FORCEINLINE
   map(BOOST_RV_REF(map) x, const allocator_type &a)
      : base_t(BOOST_MOVE_BASE(base_t, x), a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Makes *this a copy of x.
   //!
   //! Complexity: Linear in x.size().
   BOOST_CONTAINER_FORCEINLINE
   map& operator=(BOOST_COPY_ASSIGN_REF(map) x)
   {  return static_cast<map&>(this->base_t::operator=(static_cast<const base_t&>(x)));  }

   //! Effects: this->swap(x.get()).
   //!
   //! Throws: If allocator_traits_type::propagate_on_container_move_assignment
   //!   is false and (allocation throws or value_type's move constructor throws)
   //!
   //! Complexity: Constant if allocator_traits_type::
   //!   propagate_on_container_move_assignment is true or
   //!   this->get>allocator() == x.get_allocator(). Linear otherwise.
   BOOST_CONTAINER_FORCEINLINE
   map& operator=(BOOST_RV_REF(map) x)
      BOOST_NOEXCEPT_IF( (allocator_traits_type::propagate_on_container_move_assignment::value ||
                          allocator_traits_type::is_always_equal::value) &&
                           boost::container::container_detail::is_nothrow_move_assignable<Compare>::value)
   {  return static_cast<map&>(this->base_t::operator=(BOOST_MOVE_BASE(base_t, x)));  }

#if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
   //! Effects: Assign content of il to *this.
   //!
   BOOST_CONTAINER_FORCEINLINE
   map& operator=(std::initializer_list<value_type> il)
   {
       this->clear();
       insert(il.begin(), il.end());
       return *this;
   }
#endif

   #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   //! Effects: Returns a copy of the allocator that
   //!   was passed to the object's constructor.
   //!
   //! Complexity: Constant.
   allocator_type get_allocator() const;

   //! Effects: Returns a reference to the internal allocator.
   //!
   //! Throws: Nothing
   //!
   //! Complexity: Constant.
   //!
   //! Note: Non-standard extension.
   stored_allocator_type &get_stored_allocator() BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a reference to the internal allocator.
   //!
   //! Throws: Nothing
   //!
   //! Complexity: Constant.
   //!
   //! Note: Non-standard extension.
   const stored_allocator_type &get_stored_allocator() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns an iterator to the first element contained in the container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   iterator begin() BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a const_iterator to the first element contained in the container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   const_iterator begin() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a const_iterator to the first element contained in the container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   const_iterator cbegin() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns an iterator to the end of the container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   iterator end() BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a const_iterator to the end of the container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   const_iterator end() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a const_iterator to the end of the container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   const_iterator cend() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a reverse_iterator pointing to the beginning
   //! of the reversed container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   reverse_iterator rbegin() BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a const_reverse_iterator pointing to the beginning
   //! of the reversed container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   const_reverse_iterator rbegin() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a const_reverse_iterator pointing to the beginning
   //! of the reversed container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   const_reverse_iterator crbegin() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a reverse_iterator pointing to the end
   //! of the reversed container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   reverse_iterator rend() BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a const_reverse_iterator pointing to the end
   //! of the reversed container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   const_reverse_iterator rend() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns a const_reverse_iterator pointing to the end
   //! of the reversed container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   const_reverse_iterator crend() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns true if the container contains no elements.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   bool empty() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns the number of the elements contained in the container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   size_type size() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns the largest possible size of the container.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   size_type max_size() const BOOST_NOEXCEPT_OR_NOTHROW;

   #endif   //#if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
   //! Effects: If there is no key equivalent to x in the map, inserts
   //! value_type(x, T()) into the map.
   //!
   //! Returns: A reference to the mapped_type corresponding to x in *this.
   //!
   //! Complexity: Logarithmic.
   mapped_type& operator[](const key_type &k);

   //! Effects: If there is no key equivalent to x in the map, inserts
   //! value_type(boost::move(x), T()) into the map (the key is move-constructed)
   //!
   //! Returns: A reference to the mapped_type corresponding to x in *this.
   //!
   //! Complexity: Logarithmic.
   mapped_type& operator[](key_type &&k);
   #elif defined(BOOST_MOVE_HELPERS_RETURN_SFINAE_BROKEN)
      //in compilers like GCC 3.4, we can't catch temporaries
      BOOST_CONTAINER_FORCEINLINE mapped_type& operator[](const key_type &k)         {  return this->priv_subscript(k);  }
      BOOST_CONTAINER_FORCEINLINE mapped_type& operator[](BOOST_RV_REF(key_type) k)  {  return this->priv_subscript(::boost::move(k));  }
   #else
      BOOST_MOVE_CONVERSION_AWARE_CATCH( operator[] , key_type, mapped_type&, this->priv_subscript)
   #endif

   //! Effects: If a key equivalent to k already exists in the container, assigns forward<M>(obj)
   //! to the mapped_type corresponding to the key k. If the key does not exist, inserts the new value
   //! as if by insert, constructing it from value_type(k, forward<M>(obj)).
   //!
   //! No iterators or references are invalidated. If the insertion is successful, pointers and references
   //! to the element obtained while it is held in the node handle are invalidated, and pointers and
   //! references obtained to that element before it was extracted become valid.
   //!
   //! Returns: The bool component is true if the insertion took place and false if the assignment
   //!   took place. The iterator component is pointing at the element that was inserted or updated.
   //!
   //! Complexity: Logarithmic in the size of the container.
   template <class M>
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator, bool> insert_or_assign(const key_type& k, BOOST_FWD_REF(M) obj)
   {  return this->base_t::insert_or_assign(const_iterator(), k, ::boost::forward<M>(obj));  }

   //! Effects: If a key equivalent to k already exists in the container, assigns forward<M>(obj)
   //! to the mapped_type corresponding to the key k. If the key does not exist, inserts the new value
   //! as if by insert, constructing it from value_type(k, move(obj)).
   //!
   //! No iterators or references are invalidated. If the insertion is successful, pointers and references
   //! to the element obtained while it is held in the node handle are invalidated, and pointers and
   //! references obtained to that element before it was extracted become valid.
   //!
   //! Returns: The bool component is true if the insertion took place and false if the assignment
   //!   took place. The iterator component is pointing at the element that was inserted or updated.
   //!
   //! Complexity: Logarithmic in the size of the container.
   template <class M>
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator, bool> insert_or_assign(BOOST_RV_REF(key_type) k, BOOST_FWD_REF(M) obj)
   {  return this->base_t::insert_or_assign(const_iterator(), ::boost::move(k), ::boost::forward<M>(obj));  }

   //! Effects: If a key equivalent to k already exists in the container, assigns forward<M>(obj)
   //! to the mapped_type corresponding to the key k. If the key does not exist, inserts the new value
   //! as if by insert, constructing it from value_type(k, forward<M>(obj)) and the new element
   //! to the container as close as possible to the position just before hint.
   //!
   //! No iterators or references are invalidated. If the insertion is successful, pointers and references
   //! to the element obtained while it is held in the node handle are invalidated, and pointers and
   //! references obtained to that element before it was extracted become valid.
   //!
   //! Returns: The bool component is true if the insertion took place and false if the assignment
   //!   took place. The iterator component is pointing at the element that was inserted or updated.
   //!
   //! Complexity: Logarithmic in the size of the container in general, but amortized constant if
   //! the new element is inserted just before hint.
   template <class M>
   BOOST_CONTAINER_FORCEINLINE iterator insert_or_assign(const_iterator hint, const key_type& k, BOOST_FWD_REF(M) obj)
   {  return this->base_t::insert_or_assign(hint, k, ::boost::forward<M>(obj));  }

   //! Effects: If a key equivalent to k already exists in the container, assigns forward<M>(obj)
   //! to the mapped_type corresponding to the key k. If the key does not exist, inserts the new value
   //! as if by insert, constructing it from value_type(k, move(obj)) and the new element
   //! to the container as close as possible to the position just before hint.
   //!
   //! No iterators or references are invalidated. If the insertion is successful, pointers and references
   //! to the element obtained while it is held in the node handle are invalidated, and pointers and
   //! references obtained to that element before it was extracted become valid.
   //!
   //! Returns: The bool component is true if the insertion took place and false if the assignment
   //!   took place. The iterator component is pointing at the element that was inserted or updated.
   //!
   //! Complexity: Logarithmic in the size of the container in general, but amortized constant if
   //! the new element is inserted just before hint.
   template <class M>
   BOOST_CONTAINER_FORCEINLINE iterator insert_or_assign(const_iterator hint, BOOST_RV_REF(key_type) k, BOOST_FWD_REF(M) obj)
   {  return this->base_t::insert_or_assign(hint, ::boost::move(k), ::boost::forward<M>(obj));  }

   //! Returns: A reference to the element whose key is equivalent to x.
   //! Throws: An exception object of type out_of_range if no such element is present.
   //! Complexity: logarithmic.
   T& at(const key_type& k)
   {
      iterator i = this->find(k);
      if(i == this->end()){
         throw_out_of_range("map::at key not found");
      }
      return i->second;
   }

   //! Returns: A reference to the element whose key is equivalent to x.
   //! Throws: An exception object of type out_of_range if no such element is present.
   //! Complexity: logarithmic.
   const T& at(const key_type& k) const
   {
      const_iterator i = this->find(k);
      if(i == this->end()){
         throw_out_of_range("map::at key not found");
      }
      return i->second;
   }

   //////////////////////////////////////////////
   //
   //                modifiers
   //
   //////////////////////////////////////////////

   //! Effects: Inserts x if and only if there is no element in the container
   //!   with key equivalent to the key of x.
   //!
   //! Returns: The bool component of the returned pair is true if and only
   //!   if the insertion takes place, and the iterator component of the pair
   //!   points to the element with key equivalent to the key of x.
   //!
   //! Complexity: Logarithmic.
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator,bool> insert(const value_type& x)
   { return this->base_t::insert_unique(x); }

   //! Effects: Inserts a new value_type created from the pair if and only if
   //! there is no element in the container  with key equivalent to the key of x.
   //!
   //! Returns: The bool component of the returned pair is true if and only
   //!   if the insertion takes place, and the iterator component of the pair
   //!   points to the element with key equivalent to the key of x.
   //!
   //! Complexity: Logarithmic.
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator,bool> insert(const nonconst_value_type& x)
   { return this->try_emplace(x.first, x.second); }

   //! Effects: Inserts a new value_type move constructed from the pair if and
   //! only if there is no element in the container with key equivalent to the key of x.
   //!
   //! Returns: The bool component of the returned pair is true if and only
   //!   if the insertion takes place, and the iterator component of the pair
   //!   points to the element with key equivalent to the key of x.
   //!
   //! Complexity: Logarithmic.
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator,bool> insert(BOOST_RV_REF(nonconst_value_type) x)
   { return this->try_emplace(boost::move(x.first), boost::move(x.second)); }

   //! Effects: Inserts a new value_type move constructed from the pair if and
   //! only if there is no element in the container with key equivalent to the key of x.
   //!
   //! Returns: The bool component of the returned pair is true if and only
   //!   if the insertion takes place, and the iterator component of the pair
   //!   points to the element with key equivalent to the key of x.
   //!
   //! Complexity: Logarithmic.
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator,bool> insert(BOOST_RV_REF(movable_value_type) x)
   { return this->try_emplace(boost::move(x.first), boost::move(x.second)); }

   //! Effects: Move constructs a new value from x if and only if there is
   //!   no element in the container with key equivalent to the key of x.
   //!
   //! Returns: The bool component of the returned pair is true if and only
   //!   if the insertion takes place, and the iterator component of the pair
   //!   points to the element with key equivalent to the key of x.
   //!
   //! Complexity: Logarithmic.
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator,bool> insert(BOOST_RV_REF(value_type) x)
   { return this->base_t::insert_unique(boost::move(x)); }

   //! Effects: Inserts a copy of x in the container if and only if there is
   //!   no element in the container with key equivalent to the key of x.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent
   //!   to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   BOOST_CONTAINER_FORCEINLINE iterator insert(const_iterator p, const value_type& x)
   { return this->base_t::insert_unique(p, x); }

   //! Effects: Move constructs a new value from x if and only if there is
   //!   no element in the container with key equivalent to the key of x.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent
   //!   to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   iterator insert(const_iterator p, BOOST_RV_REF(nonconst_value_type) x)
   { return this->try_emplace(p, boost::move(x.first), boost::move(x.second)); }

   //! Effects: Move constructs a new value from x if and only if there is
   //!   no element in the container with key equivalent to the key of x.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent
   //!   to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   iterator insert(const_iterator p, BOOST_RV_REF(movable_value_type) x)
   { return this->try_emplace(p, boost::move(x.first), boost::move(x.second)); }

   //! Effects: Inserts a copy of x in the container.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent to the key of x.
   //!
   //! Complexity: Logarithmic.
   iterator insert(const_iterator p, const nonconst_value_type& x)
   { return this->try_emplace(p, x.first, x.second); }

   //! Effects: Inserts an element move constructed from x in the container.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent to the key of x.
   //!
   //! Complexity: Logarithmic.
   iterator insert(const_iterator p, BOOST_RV_REF(value_type) x)
   { return this->base_t::insert_unique(p, boost::move(x)); }

   //! Requires: first, last are not iterators into *this.
   //!
   //! Effects: inserts each element from the range [first,last) if and only
   //!   if there is no element with key equivalent to the key of that element.
   //!
   //! Complexity: At most N log(size()+N) (N is the distance from first to last)
   template <class InputIterator>
   BOOST_CONTAINER_FORCEINLINE void insert(InputIterator first, InputIterator last)
   {  this->base_t::insert_unique(first, last);  }

#if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
   //! Effects: inserts each element from the range [il.begin(), il.end()) if and only
   //!   if there is no element with key equivalent to the key of that element.
   //!
   //! Complexity: At most N log(size()+N) (N is the distance from il.begin() to il.end())
   BOOST_CONTAINER_FORCEINLINE void insert(std::initializer_list<value_type> il)
   {  this->base_t::insert_unique(il.begin(), il.end()); }
#endif

   //! Requires: nh is empty or this->get_allocator() == nh.get_allocator().
   //!
   //! Effects: If nh is empty, has no effect. Otherwise, inserts the element owned
   //!   by nh if and only if there is no element in the container with a key equivalent to nh.key().
   //!
   //! Returns: If nh is empty, insert_return_type.inserted is false, insert_return_type.position
   //!   is end(), and insert_return_type.node is empty. Otherwise if the insertion took place,
   //!   insert_return_type.inserted is true, insert_return_type.position points to the inserted element,
   //!   and insert_return_type.node is empty; if the insertion failed, insert_return_type.inserted is
   //!   false, insert_return_type.node has the previous value of nh, and insert_return_type.position
   //!   points to an element with a key equivalent to nh.key().
   //!
   //! Complexity: Logarithmic
   insert_return_type insert(BOOST_RV_REF_BEG_IF_CXX11 node_type BOOST_RV_REF_END_IF_CXX11 nh)
   {
      typename base_t::node_type  n(boost::move(nh));
      typename base_t::insert_return_type base_ret(this->base_t::insert_unique_node(boost::move(n)));
      return insert_return_type (base_ret.inserted, base_ret.position, boost::move(base_ret.node));
   }

   //! Effects: Same as `insert(node_type && nh)` but the element is inserted as close as possible
   //!   to the position just prior to "hint".
   //!
   //! Complexity: logarithmic in general, but amortized constant if the element is inserted
   //!   right before "hint".
   insert_return_type insert(const_iterator hint, BOOST_RV_REF_BEG_IF_CXX11 node_type BOOST_RV_REF_END_IF_CXX11 nh)
   {
      typename base_t::node_type  n(boost::move(nh));
      typename base_t::insert_return_type base_ret(this->base_t::insert_unique_node(hint, boost::move(n)));
      return insert_return_type (base_ret.inserted, base_ret.position, boost::move(base_ret.node));
   }

   #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) || defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   //! Effects: Inserts an object x of type T constructed with
   //!   std::forward<Args>(args)... in the container if and only if there is
   //!   no element in the container with an equivalent key.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: The bool component of the returned pair is true if and only
   //!   if the insertion takes place, and the iterator component of the pair
   //!   points to the element with key equivalent to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   template <class... Args>
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator,bool> emplace(BOOST_FWD_REF(Args)... args)
   {  return this->base_t::emplace_unique(boost::forward<Args>(args)...); }

   //! Effects: Inserts an object of type T constructed with
   //!   std::forward<Args>(args)... in the container if and only if there is
   //!   no element in the container with an equivalent key.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent
   //!   to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   template <class... Args>
   BOOST_CONTAINER_FORCEINLINE iterator emplace_hint(const_iterator p, BOOST_FWD_REF(Args)... args)
   {  return this->base_t::emplace_hint_unique(p, boost::forward<Args>(args)...); }

   //! Requires: value_type shall be EmplaceConstructible into map from piecewise_construct,
   //! forward_as_tuple(k), forward_as_tuple(forward<Args>(args)...).
   //!
   //! Effects: If the map already contains an element whose key is equivalent to k, there is no effect. Otherwise
   //! inserts an object of type value_type constructed with piecewise_construct, forward_as_tuple(k),
   //! forward_as_tuple(forward<Args>(args)...).
   //!
   //! Returns: The bool component of the returned pair is true if and only if the
   //! insertion took place. The returned iterator points to the map element whose key is equivalent to k.
   //!
   //! Complexity: Logarithmic.
   template <class... Args>
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator, bool> try_emplace(const key_type& k, BOOST_FWD_REF(Args)... args)
   {  return this->base_t::try_emplace(const_iterator(), k, boost::forward<Args>(args)...); }

   //! Requires: value_type shall be EmplaceConstructible into map from piecewise_construct,
   //! forward_as_tuple(k), forward_as_tuple(forward<Args>(args)...).
   //!
   //! Effects: If the map already contains an element whose key is equivalent to k, there is no effect. Otherwise
   //! inserts an object of type value_type constructed with piecewise_construct, forward_as_tuple(k),
   //! forward_as_tuple(forward<Args>(args)...).
   //!
   //! Returns: The returned iterator points to the map element whose key is equivalent to k.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if value
   //!   is inserted right before p.
   template <class... Args>
   BOOST_CONTAINER_FORCEINLINE iterator try_emplace(const_iterator hint, const key_type &k, BOOST_FWD_REF(Args)... args)
   {  return this->base_t::try_emplace(hint, k, boost::forward<Args>(args)...).first; }

   //! Requires: value_type shall be EmplaceConstructible into map from piecewise_construct,
   //! forward_as_tuple(move(k)), forward_as_tuple(forward<Args>(args)...).
   //!
   //! Effects: If the map already contains an element whose key is equivalent to k, there is no effect. Otherwise
   //! inserts an object of type value_type constructed with piecewise_construct, forward_as_tuple(move(k)),
   //! forward_as_tuple(forward<Args>(args)...).
   //!
   //! Returns: The bool component of the returned pair is true if and only if the
   //! insertion took place. The returned iterator points to the map element whose key is equivalent to k.
   //!
   //! Complexity: Logarithmic.
   template <class... Args>
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator, bool> try_emplace(BOOST_RV_REF(key_type) k, BOOST_FWD_REF(Args)... args)
   {  return this->base_t::try_emplace(const_iterator(), boost::move(k), boost::forward<Args>(args)...); }

   //! Requires: value_type shall be EmplaceConstructible into map from piecewise_construct,
   //! forward_as_tuple(move(k)), forward_as_tuple(forward<Args>(args)...).
   //!
   //! Effects: If the map already contains an element whose key is equivalent to k, there is no effect. Otherwise
   //! inserts an object of type value_type constructed with piecewise_construct, forward_as_tuple(move(k)),
   //! forward_as_tuple(forward<Args>(args)...).
   //!
   //! Returns: The returned iterator points to the map element whose key is equivalent to k.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if value
   //!   is inserted right before p.
   template <class... Args>
   BOOST_CONTAINER_FORCEINLINE iterator try_emplace(const_iterator hint, BOOST_RV_REF(key_type) k, BOOST_FWD_REF(Args)... args)
   {  return this->base_t::try_emplace(hint, boost::move(k), boost::forward<Args>(args)...).first; }

   #else // !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)

   #define BOOST_CONTAINER_MAP_EMPLACE_CODE(N) \
   BOOST_MOVE_TMPL_LT##N BOOST_MOVE_CLASS##N BOOST_MOVE_GT##N \
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator,bool> emplace(BOOST_MOVE_UREF##N)\
   {  return this->base_t::emplace_unique(BOOST_MOVE_FWD##N);   }\
   \
   BOOST_MOVE_TMPL_LT##N BOOST_MOVE_CLASS##N BOOST_MOVE_GT##N \
   BOOST_CONTAINER_FORCEINLINE iterator emplace_hint(const_iterator hint BOOST_MOVE_I##N BOOST_MOVE_UREF##N)\
   {  return this->base_t::emplace_hint_unique(hint BOOST_MOVE_I##N BOOST_MOVE_FWD##N);  }\
   \
   BOOST_MOVE_TMPL_LT##N BOOST_MOVE_CLASS##N BOOST_MOVE_GT##N \
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator, bool> try_emplace(const key_type& k BOOST_MOVE_I##N BOOST_MOVE_UREF##N)\
   {  return this->base_t::try_emplace(const_iterator(), k BOOST_MOVE_I##N BOOST_MOVE_FWD##N); }\
   \
   BOOST_MOVE_TMPL_LT##N BOOST_MOVE_CLASS##N BOOST_MOVE_GT##N \
   BOOST_CONTAINER_FORCEINLINE iterator try_emplace(const_iterator hint, const key_type &k BOOST_MOVE_I##N BOOST_MOVE_UREF##N)\
   {  return this->base_t::try_emplace(hint, k BOOST_MOVE_I##N BOOST_MOVE_FWD##N).first; }\
   \
   BOOST_MOVE_TMPL_LT##N BOOST_MOVE_CLASS##N BOOST_MOVE_GT##N \
   BOOST_CONTAINER_FORCEINLINE std::pair<iterator, bool> try_emplace(BOOST_RV_REF(key_type) k BOOST_MOVE_I##N BOOST_MOVE_UREF##N)\
   {  return this->base_t::try_emplace(const_iterator(), boost::move(k) BOOST_MOVE_I##N BOOST_MOVE_FWD##N); }\
   \
   BOOST_MOVE_TMPL_LT##N BOOST_MOVE_CLASS##N BOOST_MOVE_GT##N \
   BOOST_CONTAINER_FORCEINLINE iterator try_emplace(const_iterator hint, BOOST_RV_REF(key_type) k BOOST_MOVE_I##N BOOST_MOVE_UREF##N)\
   {  return this->base_t::try_emplace(hint, boost::move(k) BOOST_MOVE_I##N BOOST_MOVE_FWD##N).first; }\
   //
   BOOST_MOVE_ITERATE_0TO9(BOOST_CONTAINER_MAP_EMPLACE_CODE)
   #undef BOOST_CONTAINER_MAP_EMPLACE_CODE

   #endif   // !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)

   #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   //! Effects: Erases the element pointed to by p.
   //!
   //! Returns: Returns an iterator pointing to the element immediately
   //!   following q prior to the element being erased. If no such element exists,
   //!   returns end().
   //!
   //! Complexity: Amortized constant time
   iterator erase(const_iterator p) BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Erases all elements in the container with key equivalent to x.
   //!
   //! Returns: Returns the number of erased elements.
   //!
   //! Complexity: log(size()) + count(k)
   size_type erase(const key_type& x) BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Erases all the elements in the range [first, last).
   //!
   //! Returns: Returns last.
   //!
   //! Complexity: log(size())+N where N is the distance from first to last.
   iterator erase(const_iterator first, const_iterator last) BOOST_NOEXCEPT_OR_NOTHROW;

   #endif

   //! Effects: Removes the first element in the container with key equivalent to k.
   //!
   //! Returns: A node_type owning the element if found, otherwise an empty node_type.
   //!
   //! Complexity: log(a.size()).
   node_type extract(const key_type& k)
   {
      typename base_t::node_type base_nh(this->base_t::extract(k));
      node_type nh(boost::move(base_nh));
      return BOOST_MOVE_RET(node_type, nh);
   }

   //! Effects: Removes the element pointed to by "position".
   //!
   //! Returns: A node_type owning the element, otherwise an empty node_type.
   //!
   //! Complexity: Amortized constant.
   node_type extract(const_iterator position)
   {
      typename base_t::node_type base_nh(this->base_t::extract(position));
      node_type nh(boost::move(base_nh));
      return BOOST_MOVE_RET(node_type, nh);
   }

   //! Requires: this->get_allocator() == source.get_allocator().
   //!
   //! Effects: Attempts to extract each element in source and insert it into a using
   //!   the comparison object of *this. If there is an element in a with key equivalent to the
   //!   key of an element from source, then that element is not extracted from source.
   //!
   //! Postcondition: Pointers and references to the transferred elements of source refer
   //!   to those same elements but as members of *this. Iterators referring to the transferred
   //!   elements will continue to refer to their elements, but they now behave as iterators into *this,
   //!   not into source.
   //!
   //! Throws: Nothing unless the comparison object throws.
   //!
   //! Complexity: N log(a.size() + N) (N has the value source.size())
   template<class C2>
   BOOST_CONTAINER_FORCEINLINE void merge(map<Key, T, C2, Allocator, Options>& source)
   {
      typedef container_detail::tree
         <value_type_impl, select_1st_t, C2, Allocator, Options> base2_t;
      this->merge_unique(static_cast<base2_t&>(source));
   }

   //! @copydoc ::boost::container::map::merge(map<Key, T, C2, Allocator, Options>&)
   template<class C2>
   BOOST_CONTAINER_FORCEINLINE void merge(BOOST_RV_REF_BEG map<Key, T, C2, Allocator, Options> BOOST_RV_REF_END source)
   {  return this->merge(static_cast<map<Key, T, C2, Allocator, Options>&>(source)); }

   //! @copydoc ::boost::container::map::merge(map<Key, T, C2, Allocator, Options>&)
   template<class C2>
   BOOST_CONTAINER_FORCEINLINE void merge(multimap<Key, T, C2, Allocator, Options>& source)
   {
      typedef container_detail::tree
         <value_type_impl, select_1st_t, C2, Allocator, Options> base2_t;
      this->base_t::merge_unique(static_cast<base2_t&>(source));
   }

   //! @copydoc ::boost::container::map::merge(map<Key, T, C2, Allocator, Options>&)
   template<class C2>
   BOOST_CONTAINER_FORCEINLINE void merge(BOOST_RV_REF_BEG multimap<Key, T, C2, Allocator, Options> BOOST_RV_REF_END source)
   {  return this->merge(static_cast<multimap<Key, T, C2, Allocator, Options>&>(source)); }

   #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
   //! Effects: Swaps the contents of *this and x.
   //!
   //! Throws: Nothing.
   //!
   //! Complexity: Constant.
   void swap(map& x)
      BOOST_NOEXCEPT_IF(  allocator_traits_type::is_always_equal::value
                                 && boost::container::container_detail::is_nothrow_swappable<Compare>::value )

   //! Effects: erase(a.begin(),a.end()).
   //!
   //! Postcondition: size() == 0.
   //!
   //! Complexity: linear in size().
   void clear() BOOST_NOEXCEPT_OR_NOTHROW;

   //! Effects: Returns the comparison object out
   //!   of which a was constructed.
   //!
   //! Complexity: Constant.
   key_compare key_comp() const;

   //! Effects: Returns an object of value_compare constructed out
   //!   of the comparison object.
   //!
   //! Complexity: Constant.
   value_compare value_comp() const;

   //! Returns: An iterator pointing to an element with the key
   //!   equivalent to x, or end() if such an element is not found.
   //!
   //! Complexity: Logarithmic.
   iterator find(const key_type& x);

   //! Returns: A const_iterator pointing to an element with the key
   //!   equivalent to x, or end() if such an element is not found.
   //!
   //! Complexity: Logarithmic.
   const_iterator find(const key_type& x) const;

   #endif   //#if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   //! Returns: The number of elements with key equivalent to x.
   //!
   //! Complexity: log(size())+count(k)
   BOOST_CONTAINER_FORCEINLINE size_type count(const key_type& x) const
   {  return static_cast<size_type>(this->find(x) != this->cend());  }

   #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   //! Returns: An iterator pointing to the first element with key not less
   //!   than k, or a.end() if such an element is not found.
   //!
   //! Complexity: Logarithmic
   iterator lower_bound(const key_type& x);

   //! Returns: A const iterator pointing to the first element with key not
   //!   less than k, or a.end() if such an element is not found.
   //!
   //! Complexity: Logarithmic
   const_iterator lower_bound(const key_type& x) const;

   //! Returns: An iterator pointing to the first element with key not less
   //!   than x, or end() if such an element is not found.
   //!
   //! Complexity: Logarithmic
   iterator upper_bound(const key_type& x);

   //! Returns: A const iterator pointing to the first element with key not
   //!   less than x, or end() if such an element is not found.
   //!
   //! Complexity: Logarithmic
   const_iterator upper_bound(const key_type& x) const;

   //! Effects: Equivalent to std::make_pair(this->lower_bound(k), this->upper_bound(k)).
   //!
   //! Complexity: Logarithmic
   std::pair<iterator,iterator> equal_range(const key_type& x);

   //! Effects: Equivalent to std::make_pair(this->lower_bound(k), this->upper_bound(k)).
   //!
   //! Complexity: Logarithmic
   std::pair<const_iterator,const_iterator> equal_range(const key_type& x) const;

   //! Effects: Rebalances the tree. It's a no-op for Red-Black and AVL trees.
   //!
   //! Complexity: Linear
   void rebalance();

   //! Effects: Returns true if x and y are equal
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator==(const map& x, const map& y);

   //! Effects: Returns true if x and y are unequal
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator!=(const map& x, const map& y);

   //! Effects: Returns true if x is less than y
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator<(const map& x, const map& y);

   //! Effects: Returns true if x is greater than y
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator>(const map& x, const map& y);

   //! Effects: Returns true if x is equal or less than y
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator<=(const map& x, const map& y);

   //! Effects: Returns true if x is equal or greater than y
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator>=(const map& x, const map& y);

   //! Effects: x.swap(y)
   //!
   //! Complexity: Constant.
   friend void swap(map& x, map& y);

   #endif   //#if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
   private:
   template<class KeyConvertible>
   BOOST_CONTAINER_FORCEINLINE mapped_type& priv_subscript(BOOST_FWD_REF(KeyConvertible) k)
   {
      return this->try_emplace(boost::forward<KeyConvertible>(k)).first->second;
   }
   #endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
};

#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED

}  //namespace container {

//!has_trivial_destructor_after_move<> == true_type
//!specialization for optimizations
template <class Key, class T, class Compare, class Allocator>
struct has_trivial_destructor_after_move<boost::container::map<Key, T, Compare, Allocator> >
{
   typedef typename ::boost::container::allocator_traits<Allocator>::pointer pointer;
   static const bool value = ::boost::has_trivial_destructor_after_move<Allocator>::value &&
                             ::boost::has_trivial_destructor_after_move<pointer>::value &&
                             ::boost::has_trivial_destructor_after_move<Compare>::value;
};

namespace container {

#endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED

#ifdef BOOST_CONTAINER_DOXYGEN_INVOKED

//! A multimap is a kind of associative container that supports equivalent keys
//! (possibly containing multiple copies of the same key value) and provides for
//! fast retrieval of values of another type T based on the keys. The multimap class
//! supports bidirectional iterators.
//!
//! A multimap satisfies all of the requirements of a container and of a reversible
//! container and of an associative container. The value_type stored
//! by this container is the value_type is std::pair<const Key, T>.
//!
//! \tparam Key is the key_type of the map
//! \tparam Value is the mapped_type
//! \tparam Compare is the ordering function for Keys (e.g. std::less<Key>).
//! \tparam Allocator is the allocator to allocate the value_types
//!   (e.g. allocator< std::pair<const Key, T> > ).
//! \tparam Options is an packed option type generated using using boost::container::tree_assoc_options.
template < class Key, class T, class Compare = std::less<Key>
         , class Allocator = new_allocator< std::pair< const Key, T> >, class Options = tree_assoc_defaults>
#else
template <class Key, class T, class Compare, class Allocator, class Options>
#endif
class multimap
   ///@cond
   : public container_detail::tree
      < std::pair<const Key, T>
      , container_detail::select1st<Key>
      , Compare, Allocator, Options>
   ///@endcond
{
   #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
   private:
   BOOST_COPYABLE_AND_MOVABLE(multimap)

   typedef container_detail::select1st<Key>                                      select_1st_t;
   typedef std::pair<const Key, T>                                               value_type_impl;
   typedef container_detail::tree
      <value_type_impl, select_1st_t, Compare, Allocator, Options>               base_t;
   typedef container_detail::pair <Key, T>                                       movable_value_type_impl;
   typedef typename base_t::value_compare                                        value_compare_impl;
   #endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED

   typedef ::boost::container::allocator_traits<Allocator>                       allocator_traits_type;

   public:
   //////////////////////////////////////////////
   //
   //                    types
   //
   //////////////////////////////////////////////

   typedef Key                                                                      key_type;
   typedef T                                                                        mapped_type;
   typedef std::pair<const Key, T>                                                  value_type;
   typedef typename boost::container::allocator_traits<Allocator>::pointer          pointer;
   typedef typename boost::container::allocator_traits<Allocator>::const_pointer    const_pointer;
   typedef typename boost::container::allocator_traits<Allocator>::reference        reference;
   typedef typename boost::container::allocator_traits<Allocator>::const_reference  const_reference;
   typedef typename boost::container::allocator_traits<Allocator>::size_type        size_type;
   typedef typename boost::container::allocator_traits<Allocator>::difference_type  difference_type;
   typedef Allocator                                                                allocator_type;
   typedef typename BOOST_CONTAINER_IMPDEF(base_t::stored_allocator_type)           stored_allocator_type;
   typedef BOOST_CONTAINER_IMPDEF(value_compare_impl)                               value_compare;
   typedef Compare                                                                  key_compare;
   typedef typename BOOST_CONTAINER_IMPDEF(base_t::iterator)                        iterator;
   typedef typename BOOST_CONTAINER_IMPDEF(base_t::const_iterator)                  const_iterator;
   typedef typename BOOST_CONTAINER_IMPDEF(base_t::reverse_iterator)                reverse_iterator;
   typedef typename BOOST_CONTAINER_IMPDEF(base_t::const_reverse_iterator)          const_reverse_iterator;
   typedef std::pair<key_type, mapped_type>                                         nonconst_value_type;
   typedef BOOST_CONTAINER_IMPDEF(movable_value_type_impl)                          movable_value_type;
   typedef BOOST_CONTAINER_IMPDEF(node_handle<
      typename base_t::node_type::container_node_type
      BOOST_MOVE_I value_type
      BOOST_MOVE_I allocator_type
      BOOST_MOVE_I pair_key_mapped_of_value
         <key_type BOOST_MOVE_I mapped_type> >)                                     node_type;

   //////////////////////////////////////////////
   //
   //          construct/copy/destroy
   //
   //////////////////////////////////////////////

   //! Effects: Default constructs an empty multimap.
   //!
   //! Complexity: Constant.
   BOOST_CONTAINER_FORCEINLINE
   multimap() BOOST_NOEXCEPT_IF(container_detail::is_nothrow_default_constructible<Allocator>::value &&
                                container_detail::is_nothrow_default_constructible<Compare>::value)
      : base_t()
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty multimap using the specified allocator.
   //!
   //! Complexity: Constant.
   BOOST_CONTAINER_FORCEINLINE
   explicit multimap(const Compare& comp, const allocator_type& a = allocator_type())
      : base_t(comp, a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty multimap using the specified comparison
   //!   object and allocator.
   //!
   //! Complexity: Constant.
   BOOST_CONTAINER_FORCEINLINE
   explicit multimap(const allocator_type& a)
      : base_t(a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty multimap using the specified comparison object
   //!   and allocator, and inserts elements from the range [first ,last ).
   //!
   //! Complexity: 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>
   BOOST_CONTAINER_FORCEINLINE
   multimap(InputIterator first, InputIterator last,
            const Compare& comp = Compare(),
            const allocator_type& a = allocator_type())
      : base_t(false, first, last, comp, a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty multimap using the specified
   //! allocator, and inserts elements from the range [first ,last ).
   //!
   //! Complexity: 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>
   BOOST_CONTAINER_FORCEINLINE multimap(InputIterator first, InputIterator last, const allocator_type& a)
      : base_t(false, first, last, Compare(), a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty multimap using the specified comparison object and
   //! allocator, and inserts elements from the ordered range [first ,last). This function
   //! is more efficient than the normal range creation for ordered ranges.
   //!
   //! Requires: [first ,last) must be ordered according to the predicate.
   //!
   //! Complexity: Linear in N.
   //!
   //! Note: Non-standard extension.
   template <class InputIterator>
   BOOST_CONTAINER_FORCEINLINE multimap(ordered_range_t, InputIterator first, InputIterator last, const Compare& comp = Compare(),
         const allocator_type& a = allocator_type())
      : base_t(ordered_range, first, last, comp, a)
   {}

#if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
   //! Effects: Constructs an empty multimap using the specified comparison object and
   //! allocator, and inserts elements from the range [il.begin(), il.end()).
   //!
   //! Complexity: Linear in N if the range [first ,last ) is already sorted using
   //! comp and otherwise N logN, where N is il.first() - il.end().
   BOOST_CONTAINER_FORCEINLINE
   multimap(std::initializer_list<value_type> il, const Compare& comp = Compare(),
           const allocator_type& a = allocator_type())
      : base_t(false, il.begin(), il.end(), comp, a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty multimap using the specified
   //! allocator, and inserts elements from the range [il.begin(), il.end()).
   //!
   //! Complexity: Linear in N if the range [first ,last ) is already sorted using
   //! comp and otherwise N logN, where N is il.first() - il.end().
   BOOST_CONTAINER_FORCEINLINE
   multimap(std::initializer_list<value_type> il, const allocator_type& a)
      : base_t(false, il.begin(), il.end(), Compare(), a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Constructs an empty set using the specified comparison object and
   //! allocator, and inserts elements from the ordered range [il.begin(), il.end()). This function
   //! is more efficient than the normal range creation for ordered ranges.
   //!
   //! Requires: [il.begin(), il.end()) must be ordered according to the predicate.
   //!
   //! Complexity: Linear in N.
   //!
   //! Note: Non-standard extension.
   BOOST_CONTAINER_FORCEINLINE
   multimap(ordered_range_t, std::initializer_list<value_type> il, const Compare& comp = Compare(),
       const allocator_type& a = allocator_type())
      : base_t(ordered_range, il.begin(), il.end(), comp, a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }
#endif

   //! Effects: Copy constructs a multimap.
   //!
   //! Complexity: Linear in x.size().
   BOOST_CONTAINER_FORCEINLINE multimap(const multimap& x)
      : base_t(static_cast<const base_t&>(x))
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Move constructs a multimap. Constructs *this using x's resources.
   //!
   //! Complexity: Constant.
   //!
   //! Postcondition: x is emptied.
   BOOST_CONTAINER_FORCEINLINE multimap(BOOST_RV_REF(multimap) x)
      BOOST_NOEXCEPT_IF(boost::container::container_detail::is_nothrow_move_constructible<Compare>::value)
      : base_t(BOOST_MOVE_BASE(base_t, x))
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Copy constructs a multimap.
   //!
   //! Complexity: Linear in x.size().
   BOOST_CONTAINER_FORCEINLINE multimap(const multimap& x, const allocator_type &a)
      : base_t(static_cast<const base_t&>(x), a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Move constructs a multimap using the specified allocator.
   //!                 Constructs *this using x's resources.
   //! Complexity: Constant if a == x.get_allocator(), linear otherwise.
   //!
   //! Postcondition: x is emptied.
   BOOST_CONTAINER_FORCEINLINE multimap(BOOST_RV_REF(multimap) x, const allocator_type &a)
      : base_t(BOOST_MOVE_BASE(base_t, x), a)
   {
      //A type must be std::pair<CONST Key, T>
      BOOST_STATIC_ASSERT((container_detail::is_same<std::pair<const Key, T>, typename Allocator::value_type>::value));
   }

   //! Effects: Makes *this a copy of x.
   //!
   //! Complexity: Linear in x.size().
   BOOST_CONTAINER_FORCEINLINE multimap& operator=(BOOST_COPY_ASSIGN_REF(multimap) x)
   {  return static_cast<multimap&>(this->base_t::operator=(static_cast<const base_t&>(x)));  }

   //! Effects: this->swap(x.get()).
   //!
   //! Complexity: Constant.
   BOOST_CONTAINER_FORCEINLINE multimap& operator=(BOOST_RV_REF(multimap) x)
      BOOST_NOEXCEPT_IF( (allocator_traits_type::propagate_on_container_move_assignment::value ||
                          allocator_traits_type::is_always_equal::value) &&
                           boost::container::container_detail::is_nothrow_move_assignable<Compare>::value)
   {  return static_cast<multimap&>(this->base_t::operator=(BOOST_MOVE_BASE(base_t, x)));  }

#if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
   //! Effects: Assign content of il to *this.
   //!
   BOOST_CONTAINER_FORCEINLINE multimap& operator=(std::initializer_list<value_type> il)
   {
       this->clear();
       insert(il.begin(), il.end());
       return *this;
   }
#endif

   #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   //! @copydoc ::boost::container::set::get_allocator()
   allocator_type get_allocator() const;

   //! @copydoc ::boost::container::set::get_stored_allocator()
   stored_allocator_type &get_stored_allocator();

   //! @copydoc ::boost::container::set::get_stored_allocator() const
   const stored_allocator_type &get_stored_allocator() const;

   //! @copydoc ::boost::container::set::begin()
   iterator begin();

   //! @copydoc ::boost::container::set::begin() const
   const_iterator begin() const;

   //! @copydoc ::boost::container::set::cbegin() const
   const_iterator cbegin() const;

   //! @copydoc ::boost::container::set::end()
   iterator end() BOOST_NOEXCEPT_OR_NOTHROW;

   //! @copydoc ::boost::container::set::end() const
   const_iterator end() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! @copydoc ::boost::container::set::cend() const
   const_iterator cend() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! @copydoc ::boost::container::set::rbegin()
   reverse_iterator rbegin() BOOST_NOEXCEPT_OR_NOTHROW;

   //! @copydoc ::boost::container::set::rbegin() const
   const_reverse_iterator rbegin() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! @copydoc ::boost::container::set::crbegin() const
   const_reverse_iterator crbegin() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! @copydoc ::boost::container::set::rend()
   reverse_iterator rend() BOOST_NOEXCEPT_OR_NOTHROW;

   //! @copydoc ::boost::container::set::rend() const
   const_reverse_iterator rend() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! @copydoc ::boost::container::set::crend() const
   const_reverse_iterator crend() const BOOST_NOEXCEPT_OR_NOTHROW;

   //! @copydoc ::boost::container::set::empty() const
   bool empty() const;

   //! @copydoc ::boost::container::set::size() const
   size_type size() const;

   //! @copydoc ::boost::container::set::max_size() const
   size_type max_size() const;

   #endif   //#if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) || defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   //! Effects: Inserts an object of type T constructed with
   //!   std::forward<Args>(args)... in the container.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent
   //!   to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   template <class... Args>
   BOOST_CONTAINER_FORCEINLINE iterator emplace(BOOST_FWD_REF(Args)... args)
   {  return this->base_t::emplace_equal(boost::forward<Args>(args)...); }

   //! Effects: Inserts an object of type T constructed with
   //!   std::forward<Args>(args)... in the container.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent
   //!   to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   template <class... Args>
   BOOST_CONTAINER_FORCEINLINE iterator emplace_hint(const_iterator p, BOOST_FWD_REF(Args)... args)
   {  return this->base_t::emplace_hint_equal(p, boost::forward<Args>(args)...); }

   #else // !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)

   #define BOOST_CONTAINER_MULTIMAP_EMPLACE_CODE(N) \
   BOOST_MOVE_TMPL_LT##N BOOST_MOVE_CLASS##N BOOST_MOVE_GT##N \
   BOOST_CONTAINER_FORCEINLINE iterator emplace(BOOST_MOVE_UREF##N)\
   {  return this->base_t::emplace_equal(BOOST_MOVE_FWD##N);   }\
   \
   BOOST_MOVE_TMPL_LT##N BOOST_MOVE_CLASS##N BOOST_MOVE_GT##N \
   BOOST_CONTAINER_FORCEINLINE iterator emplace_hint(const_iterator hint BOOST_MOVE_I##N BOOST_MOVE_UREF##N)\
   {  return this->base_t::emplace_hint_equal(hint BOOST_MOVE_I##N BOOST_MOVE_FWD##N);  }\
   //
   BOOST_MOVE_ITERATE_0TO9(BOOST_CONTAINER_MULTIMAP_EMPLACE_CODE)
   #undef BOOST_CONTAINER_MULTIMAP_EMPLACE_CODE

   #endif   // !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)

   //! Effects: Inserts x and returns the iterator pointing to the
   //!   newly inserted element.
   //!
   //! Complexity: Logarithmic.
   BOOST_CONTAINER_FORCEINLINE iterator insert(const value_type& x)
   { return this->base_t::insert_equal(x); }

   //! Effects: Inserts a new value constructed from x and returns
   //!   the iterator pointing to the newly inserted element.
   //!
   //! Complexity: Logarithmic.
   BOOST_CONTAINER_FORCEINLINE iterator insert(const nonconst_value_type& x)
   { return this->base_t::emplace_equal(x); }

   //! Effects: Inserts a new value move-constructed from x and returns
   //!   the iterator pointing to the newly inserted element.
   //!
   //! Complexity: Logarithmic.
   BOOST_CONTAINER_FORCEINLINE iterator insert(BOOST_RV_REF(nonconst_value_type) x)
   { return this->base_t::emplace_equal(boost::move(x)); }

   //! Effects: Inserts a new value move-constructed from x and returns
   //!   the iterator pointing to the newly inserted element.
   //!
   //! Complexity: Logarithmic.
   iterator insert(BOOST_RV_REF(movable_value_type) x)
   { return this->base_t::emplace_equal(boost::move(x)); }

   //! Effects: Inserts a copy of x in the container.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent
   //!   to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   BOOST_CONTAINER_FORCEINLINE iterator insert(const_iterator p, const value_type& x)
   { return this->base_t::insert_equal(p, x); }

   //! Effects: Inserts a new value constructed from x in the container.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent
   //!   to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   BOOST_CONTAINER_FORCEINLINE iterator insert(const_iterator p, const nonconst_value_type& x)
   { return this->base_t::emplace_hint_equal(p, x); }

   //! Effects: Inserts a new value move constructed from x in the container.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent
   //!   to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   BOOST_CONTAINER_FORCEINLINE iterator insert(const_iterator p, BOOST_RV_REF(nonconst_value_type) x)
   { return this->base_t::emplace_hint_equal(p, boost::move(x)); }

   //! Effects: Inserts a new value move constructed from x in the container.
   //!   p is a hint pointing to where the insert should start to search.
   //!
   //! Returns: An iterator pointing to the element with key equivalent
   //!   to the key of x.
   //!
   //! Complexity: Logarithmic in general, but amortized constant if t
   //!   is inserted right before p.
   BOOST_CONTAINER_FORCEINLINE iterator insert(const_iterator p, BOOST_RV_REF(movable_value_type) x)
   { return this->base_t::emplace_hint_equal(p, boost::move(x)); }

   //! Requires: first, last are not iterators into *this.
   //!
   //! Effects: inserts each element from the range [first,last) .
   //!
   //! Complexity: At most N log(size()+N) (N is the distance from first to last)
   template <class InputIterator>
   BOOST_CONTAINER_FORCEINLINE void insert(InputIterator first, InputIterator last)
   {  this->base_t::insert_equal(first, last); }

#if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
   //! Effects: inserts each element from the range [il.begin(), il.end().
   //!
   //! Complexity: At most N log(size()+N) (N is the distance from il.begin() to il.end())
   BOOST_CONTAINER_FORCEINLINE void insert(std::initializer_list<value_type> il)
   {  this->base_t::insert_equal(il.begin(), il.end()); }
#endif

   //! Requires: nh is empty or this->get_allocator() == nh.get_allocator().
   //!
   //! Effects/Returns: If nh is empty, has no effect and returns end(). Otherwise, inserts
   //!   the element owned by nh and returns an iterator pointing to the newly inserted element.
   //!   If a range containing elements with keys equivalent to nh.key() exists,
   //!   the element is inserted at the end of that range. nh is always emptied.
   //!
   //! Complexity: Logarithmic
   iterator insert(BOOST_RV_REF_BEG_IF_CXX11 node_type BOOST_RV_REF_END_IF_CXX11 nh)
   {
      typename base_t::node_type n(boost::move(nh));
      return this->base_t::insert_equal_node(boost::move(n));
   }

   //! Effects: Same as `insert(node_type && nh)` but the element is inserted as close as possible
   //!   to the position just prior to "hint".
   //!
   //! Complexity: logarithmic in general, but amortized constant if the element is inserted
   //!   right before "hint".
   iterator insert(const_iterator hint, BOOST_RV_REF_BEG_IF_CXX11 node_type BOOST_RV_REF_END_IF_CXX11 nh)
   {
      typename base_t::node_type n(boost::move(nh));
      return this->base_t::insert_equal_node(hint, boost::move(n));
   }

   #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)

   //! @copydoc ::boost::container::set::erase(const_iterator)
   iterator erase(const_iterator p);

   //! @copydoc ::boost::container::set::erase(const key_type&)
   size_type erase(const key_type& x);

   //! @copydoc ::boost::container::set::erase(const_iterator,const_iterator)
   iterator erase(const_iterator first, const_iterator last);
   #endif

   //! @copydoc ::boost::container::map::extract(const key_type&)
   node_type extract(const key_type& k)
   {
      typename base_t::node_type base_nh(this->base_t::extract(k));
      return node_type(boost::move(base_nh));
   }

   //! @copydoc ::boost::container::map::extract(const_iterator)
   node_type extract(const_iterator position)
   {
      typename base_t::node_type base_nh(this->base_t::extract(position));
      return node_type (boost::move(base_nh));
   }

   //! Requires: this->get_allocator() == source.get_allocator().
   //!
   //! Effects: Extracts each element in source and insert it into a using
   //!   the comparison object of *this.
   //!
   //! Postcondition: Pointers and references to the transferred elements of source refer
   //!   to those same elements but as members of *this. Iterators referring to the transferred
   //!   elements will continue to refer to their elements, but they now behave as iterators into *this,
   //!   not into source.
   //!
   //! Throws: Nothing unless the comparison object throws.
   //!
   //! Complexity: N log(a.size() + N) (N has the value source.size())
   template<class C2>
   void merge(multimap<Key, T, C2, Allocator, Options>& source)
   {
      typedef container_detail::tree
         <value_type_impl, select_1st_t, C2, Allocator, Options> base2_t;
      this->base_t::merge_equal(static_cast<base2_t&>(source));
   }

   //! @copydoc ::boost::container::multimap::merge(multimap<Key, T, C2, Allocator, Options>&)
   template<class C2>
   void merge(BOOST_RV_REF_BEG multimap<Key, T, C2, Allocator, Options> BOOST_RV_REF_END source)
   {  return this->merge(static_cast<multimap<Key, T, C2, Allocator, Options>&>(source)); }

   //! @copydoc ::boost::container::multimap::merge(multimap<Key, T, C2, Allocator, Options>&)
   template<class C2>
   void merge(map<Key, T, C2, Allocator, Options>& source)
   {
      typedef container_detail::tree
         <value_type_impl, select_1st_t, C2, Allocator, Options> base2_t;
      this->base_t::merge_equal(static_cast<base2_t&>(source));
   }

   //! @copydoc ::boost::container::multimap::merge(multimap<Key, T, C2, Allocator, Options>&)
   template<class C2>
   void merge(BOOST_RV_REF_BEG map<Key, T, C2, Allocator, Options> BOOST_RV_REF_END source)
   {  return this->merge(static_cast<map<Key, T, C2, Allocator, Options>&>(source)); }

   #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
   //! @copydoc ::boost::container::set::swap
   void swap(multiset& x)
      BOOST_NOEXCEPT_IF(  allocator_traits_type::is_always_equal::value
                                 && boost::container::container_detail::is_nothrow_swappable<Compare>::value );

   //! @copydoc ::boost::container::set::clear
   void clear() BOOST_NOEXCEPT_OR_NOTHROW;

   //! @copydoc ::boost::container::set::key_comp
   key_compare key_comp() const;

   //! @copydoc ::boost::container::set::value_comp
   value_compare value_comp() const;

   //! Returns: An iterator pointing to an element with the key
   //!   equivalent to x, or end() if such an element is not found.
   //!
   //! Complexity: Logarithmic.
   iterator find(const key_type& x);

   //! Returns: A const iterator pointing to an element with the key
   //!   equivalent to x, or end() if such an element is not found.
   //!
   //! Complexity: Logarithmic.
   const_iterator find(const key_type& x) const;

   //! Returns: The number of elements with key equivalent to x.
   //!
   //! Complexity: log(size())+count(k)
   size_type count(const key_type& x) const;

   //! Returns: An iterator pointing to the first element with key not less
   //!   than k, or a.end() if such an element is not found.
   //!
   //! Complexity: Logarithmic
   iterator lower_bound(const key_type& x);

   //! Returns: A const iterator pointing to the first element with key not
   //!   less than k, or a.end() if such an element is not found.
   //!
   //! Complexity: Logarithmic
   const_iterator lower_bound(const key_type& x) const;

   //! Returns: An iterator pointing to the first element with key not less
   //!   than x, or end() if such an element is not found.
   //!
   //! Complexity: Logarithmic
   iterator upper_bound(const key_type& x);

   //! Returns: A const iterator pointing to the first element with key not
   //!   less than x, or end() if such an element is not found.
   //!
   //! Complexity: Logarithmic
   const_iterator upper_bound(const key_type& x) const;

   //! Effects: Equivalent to std::make_pair(this->lower_bound(k), this->upper_bound(k)).
   //!
   //! Complexity: Logarithmic
   std::pair<iterator,iterator> equal_range(const key_type& x);

   //! Effects: Equivalent to std::make_pair(this->lower_bound(k), this->upper_bound(k)).
   //!
   //! Complexity: Logarithmic
   std::pair<const_iterator,const_iterator> equal_range(const key_type& x) const;

   //! Effects: Rebalances the tree. It's a no-op for Red-Black and AVL trees.
   //!
   //! Complexity: Linear
   void rebalance();

   //! Effects: Returns true if x and y are equal
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator==(const multimap& x, const multimap& y);

   //! Effects: Returns true if x and y are unequal
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator!=(const multimap& x, const multimap& y);

   //! Effects: Returns true if x is less than y
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator<(const multimap& x, const multimap& y);

   //! Effects: Returns true if x is greater than y
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator>(const multimap& x, const multimap& y);

   //! Effects: Returns true if x is equal or less than y
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator<=(const multimap& x, const multimap& y);

   //! Effects: Returns true if x is equal or greater than y
   //!
   //! Complexity: Linear to the number of elements in the container.
   friend bool operator>=(const multimap& x, const multimap& y);

   //! Effects: x.swap(y)
   //!
   //! Complexity: Constant.
   friend void swap(multimap& x, multimap& y);

   #endif   //#if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
};

#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED

}  //namespace container {

//!has_trivial_destructor_after_move<> == true_type
//!specialization for optimizations
template <class Key, class T, class Compare, class Allocator>
struct has_trivial_destructor_after_move<boost::container::multimap<Key, T, Compare, Allocator> >
{
   typedef typename ::boost::container::allocator_traits<Allocator>::pointer pointer;
   static const bool value = ::boost::has_trivial_destructor_after_move<Allocator>::value &&
                             ::boost::has_trivial_destructor_after_move<pointer>::value &&
                             ::boost::has_trivial_destructor_after_move<Compare>::value;
};

namespace container {

#endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED

}}

#include <boost/container/detail/config_end.hpp>

#endif   // BOOST_CONTAINER_MAP_HPP


code:
#ifndef BOOST_CORE_LIGHTWEIGHT_TEST_HPP
#define BOOST_CORE_LIGHTWEIGHT_TEST_HPP

// MS compatible compilers support #pragma once

#if defined(_MSC_VER)
# pragma once
#endif

//
//  boost/core/lightweight_test.hpp - lightweight test library
//
//  Copyright (c) 2002, 2009, 2014 Peter Dimov
//  Copyright (2) Beman Dawes 2010, 2011
//  Copyright (3) Ion Gaztanaga 2013
//
//  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
//

#include <boost/assert.hpp>
#include <boost/current_function.hpp>
#include <boost/core/no_exceptions_support.hpp>
#include <iostream>

//  IDE's like Visual Studio perform better if output goes to std::cout or
//  some other stream, so allow user to configure output stream:
#ifndef BOOST_LIGHTWEIGHT_TEST_OSTREAM
# define BOOST_LIGHTWEIGHT_TEST_OSTREAM std::cerr
#endif

namespace boost
{

namespace detail
{

struct report_errors_reminder
{
    bool called_report_errors_function;

    report_errors_reminder() : called_report_errors_function(false) {}

    ~report_errors_reminder()
    {
        BOOST_ASSERT(called_report_errors_function);  // verify report_errors() was called
    }
};

inline report_errors_reminder& report_errors_remind()
{
    static report_errors_reminder r;
    return r;
}

inline int & test_errors()
{
    static int x = 0;
    report_errors_remind();
    return x;
}

inline void test_failed_impl(char const * expr, char const * file, int line, char const * function)
{
    BOOST_LIGHTWEIGHT_TEST_OSTREAM
      << file << "(" << line << "): test '" << expr << "' failed in function '"
      << function << "'" << std::endl;
    ++test_errors();
}

inline void error_impl(char const * msg, char const * file, int line, char const * function)
{
    BOOST_LIGHTWEIGHT_TEST_OSTREAM
      << file << "(" << line << "): " << msg << " in function '"
      << function << "'" << std::endl;
    ++test_errors();
}

inline void throw_failed_impl(char const * excep, char const * file, int line, char const * function)
{
   BOOST_LIGHTWEIGHT_TEST_OSTREAM
    << file << "(" << line << "): Exception '" << excep << "' not thrown in function '"
    << function << "'" << std::endl;
   ++test_errors();
}

// In the comparisons below, it is possible that T and U are signed and unsigned integer types, which generates warnings in some compilers.
// A cleaner fix would require common_type trait or some meta-programming, which would introduce a dependency on Boost.TypeTraits. To avoid
// the dependency we just disable the warnings.
#if defined(_MSC_VER)
# pragma warning(push)
# pragma warning(disable: 4389)
#elif defined(__clang__) && defined(__has_warning)
# if __has_warning("-Wsign-compare")
#  pragma clang diagnostic push
#  pragma clang diagnostic ignored "-Wsign-compare"
# endif
#elif defined(__GNUC__) && !(defined(__INTEL_COMPILER) || defined(__ICL) || defined(__ICC) || defined(__ECC)) && (__GNUC__ * 100 + __GNUC_MINOR__) >= 406
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wsign-compare"
#endif

template<class T, class U> inline void test_eq_impl( char const * expr1, char const * expr2,
  char const * file, int line, char const * function, T const & t, U const & u )
{
    if( t == u )
    {
        report_errors_remind();
    }
    else
    {
        BOOST_LIGHTWEIGHT_TEST_OSTREAM
            << file << "(" << line << "): test '" << expr1 << " == " << expr2
            << "' failed in function '" << function << "': "
            << "'" << t << "' != '" << u << "'" << std::endl;
        ++test_errors();
    }
}

template<class T, class U> inline void test_ne_impl( char const * expr1, char const * expr2,
  char const * file, int line, char const * function, T const & t, U const & u )
{
    if( t != u )
    {
        report_errors_remind();
    }
    else
    {
        BOOST_LIGHTWEIGHT_TEST_OSTREAM
            << file << "(" << line << "): test '" << expr1 << " != " << expr2
            << "' failed in function '" << function << "': "
            << "'" << t << "' == '" << u << "'" << std::endl;
        ++test_errors();
    }
}

#if defined(_MSC_VER)
# pragma warning(pop)
#elif defined(__clang__) && defined(__has_warning)
# if __has_warning("-Wsign-compare")
#  pragma clang diagnostic pop
# endif
#elif defined(__GNUC__) && !(defined(__INTEL_COMPILER) || defined(__ICL) || defined(__ICC) || defined(__ECC)) && (__GNUC__ * 100 + __GNUC_MINOR__) >= 406
# pragma GCC diagnostic pop
#endif

} // namespace detail

inline int report_errors()
{
    boost::detail::report_errors_remind().called_report_errors_function = true;

    int errors = boost::detail::test_errors();

    if( errors == 0 )
    {
        BOOST_LIGHTWEIGHT_TEST_OSTREAM
          << "No errors detected." << std::endl;
        return 0;
    }
    else
    {
        BOOST_LIGHTWEIGHT_TEST_OSTREAM
          << errors << " error" << (errors == 1? "": "s") << " detected." << std::endl;
        return 1;
    }
}

} // namespace boost

#define BOOST_TEST(expr) ((expr)? (void)0: ::boost::detail::test_failed_impl(#expr, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION))
#define BOOST_TEST_NOT(expr) BOOST_TEST(!(expr))

#define BOOST_ERROR(msg) ( ::boost::detail::error_impl(msg, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION) )

#define BOOST_TEST_EQ(expr1,expr2) ( ::boost::detail::test_eq_impl(#expr1, #expr2, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION, expr1, expr2) )
#define BOOST_TEST_NE(expr1,expr2) ( ::boost::detail::test_ne_impl(#expr1, #expr2, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION, expr1, expr2) )

#ifndef BOOST_NO_EXCEPTIONS
   #define BOOST_TEST_THROWS( EXPR, EXCEP )                    \
      try {                                                    \
         EXPR;                                                 \
         ::boost::detail::throw_failed_impl                    \
         (#EXCEP, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION); \
      }                                                        \
      catch(EXCEP const&) {                                    \
      }                                                        \
      catch(...) {                                             \
         ::boost::detail::throw_failed_impl                    \
         (#EXCEP, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION); \
      }                                                        \
   //
#else
   #define BOOST_TEST_THROWS( EXPR, EXCEP )
#endif

#endif // #ifndef BOOST_CORE_LIGHTWEIGHT_TEST_HPP

license: mit


code:
// Copyright (C) 2004 The Trustees of Indiana University.
// Copyright (C) 2005-2006 Douglas Gregor <doug.gregor -at- gmail.com>

// Use, modification and distribution is subject to 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)

//  Authors: Douglas Gregor
//           Andrew Lumsdaine

/** @file operations.hpp
 *
 *  This header provides a mapping from function objects to @c MPI_Op
 *  constants used in MPI collective operations. It also provides
 *  several new function object types not present in the standard @c
 *  <functional> header that have direct mappings to @c MPI_Op.
 */
#ifndef BOOST_MPI_IS_MPI_OP_HPP
#define BOOST_MPI_IS_MPI_OP_HPP

#include <boost/mpi/config.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/and.hpp>
#include <boost/mpi/datatype.hpp>
#include <boost/utility/enable_if.hpp>
#include <functional>

namespace boost { namespace mpi {

template<typename Op, typename T> struct is_mpi_op;

/**
 * @brief Determine if a function object type is commutative.
 *
 * This trait determines if an operation @c Op is commutative when
 * applied to values of type @c T. Parallel operations such as @c
 * reduce and @c prefix_sum can be implemented more efficiently with
 * commutative operations. To mark an operation as commutative, users
 * should specialize @c is_commutative and derive from the class @c
 * mpl::true_.
 */
template<typename Op, typename T>
struct is_commutative : public mpl::false_ { };

/**************************************************************************
 * Function objects for MPI operations not in <functional> header         *
 **************************************************************************/

/**
 *  @brief Compute the maximum of two values.
 *
 *  This binary function object computes the maximum of the two values
 *  it is given. When used with MPI and a type @c T that has an
 *  associated, built-in MPI data type, translates to @c MPI_MAX.
 */
template<typename T>
struct maximum : public std::binary_function<T, T, T>
{
  /** @returns the maximum of x and y. */
  const T& operator()(const T& x, const T& y) const
  {
    return x < y? y : x;
  }
};

/**
 *  @brief Compute the minimum of two values.
 *
 *  This binary function object computes the minimum of the two values
 *  it is given. When used with MPI and a type @c T that has an
 *  associated, built-in MPI data type, translates to @c MPI_MIN.
 */
template<typename T>
struct minimum : public std::binary_function<T, T, T>
{
  /** @returns the minimum of x and y. */
  const T& operator()(const T& x, const T& y) const
  {
    return x < y? x : y;
  }
};

/**
 *  @brief Compute the bitwise AND of two integral values.
 *
 *  This binary function object computes the bitwise AND of the two
 *  values it is given. When used with MPI and a type @c T that has an
 *  associated, built-in MPI data type, translates to @c MPI_BAND.
 */
template<typename T>
struct bitwise_and : public std::binary_function<T, T, T>
{
  /** @returns @c x & y. */
  T operator()(const T& x, const T& y) const
  {
    return x & y;
  }
};

/**
 *  @brief Compute the bitwise OR of two integral values.
 *
 *  This binary function object computes the bitwise OR of the two
 *  values it is given. When used with MPI and a type @c T that has an
 *  associated, built-in MPI data type, translates to @c MPI_BOR.
 */
template<typename T>
struct bitwise_or : public std::binary_function<T, T, T>
{
  /** @returns the @c x | y. */
  T operator()(const T& x, const T& y) const
  {
    return x | y;
  }
};

/**
 *  @brief Compute the logical exclusive OR of two integral values.
 *
 *  This binary function object computes the logical exclusive of the
 *  two values it is given. When used with MPI and a type @c T that has
 *  an associated, built-in MPI data type, translates to @c MPI_LXOR.
 */
template<typename T>
struct logical_xor : public std::binary_function<T, T, T>
{
  /** @returns the logical exclusive OR of x and y. */
  T operator()(const T& x, const T& y) const
  {
    return (x || y) && !(x && y);
  }
};

/**
 *  @brief Compute the bitwise exclusive OR of two integral values.
 *
 *  This binary function object computes the bitwise exclusive OR of
 *  the two values it is given. When used with MPI and a type @c T that
 *  has an associated, built-in MPI data type, translates to @c
 *  MPI_BXOR.
 */
template<typename T>
struct bitwise_xor : public std::binary_function<T, T, T>
{
  /** @returns @c x ^ y. */
  T operator()(const T& x, const T& y) const
  {
    return x ^ y;
  }
};

/**************************************************************************
 * MPI_Op queries                                                         *
 **************************************************************************/

/**
 *  @brief Determine if a function object has an associated @c MPI_Op.
 *
 *  This trait determines if a function object type @c Op, when used
 *  with argument type @c T, has an associated @c MPI_Op. If so, @c
 *  is_mpi_op<Op,T> will derive from @c mpl::false_ and will
 *  contain a static member function @c op that takes no arguments but
 *  returns the associated @c MPI_Op value. For instance, @c
 *  is_mpi_op<std::plus<int>,int>::op() returns @c MPI_SUM.
 *
 *  Users may specialize @c is_mpi_op for any other class templates
 *  that map onto operations that have @c MPI_Op equivalences, such as
 *  bitwise OR, logical and, or maximum. However, users are encouraged
 *  to use the standard function objects in the @c functional and @c
 *  boost/mpi/operations.hpp headers whenever possible. For
 *  function objects that are class templates with a single template
 *  parameter, it may be easier to specialize @c is_builtin_mpi_op.
 */
template<typename Op, typename T>
struct is_mpi_op : public mpl::false_ { };

/// INTERNAL ONLY
template<typename T>
struct is_mpi_op<maximum<T>, T>
  : public boost::mpl::or_<is_mpi_integer_datatype<T>,
                           is_mpi_floating_point_datatype<T> >
{
  static MPI_Op op() { return MPI_MAX; }
};

/// INTERNAL ONLY
template<typename T>
struct is_mpi_op<minimum<T>, T>
  : public boost::mpl::or_<is_mpi_integer_datatype<T>,
                           is_mpi_floating_point_datatype<T> >
{
  static MPI_Op op() { return MPI_MIN; }
};

/// INTERNAL ONLY
template<typename T>
 struct is_mpi_op<std::plus<T>, T>
  : public boost::mpl::or_<is_mpi_integer_datatype<T>,
                           is_mpi_floating_point_datatype<T>,
                           is_mpi_complex_datatype<T> >
{
  static MPI_Op op() { return MPI_SUM; }
};

/// INTERNAL ONLY
template<typename T>
 struct is_mpi_op<std::multiplies<T>, T>
  : public boost::mpl::or_<is_mpi_integer_datatype<T>,
                           is_mpi_floating_point_datatype<T>,
                           is_mpi_complex_datatype<T> >
{
  static MPI_Op op() { return MPI_PROD; }
};

/// INTERNAL ONLY
template<typename T>
 struct is_mpi_op<std::logical_and<T>, T>
  : public boost::mpl::or_<is_mpi_integer_datatype<T>,
                           is_mpi_logical_datatype<T> >
{
  static MPI_Op op() { return MPI_LAND; }
};

/// INTERNAL ONLY
template<typename T>
 struct is_mpi_op<std::logical_or<T>, T>
  : public boost::mpl::or_<is_mpi_integer_datatype<T>,
                           is_mpi_logical_datatype<T> >
{
  static MPI_Op op() { return MPI_LOR; }
};

/// INTERNAL ONLY
template<typename T>
 struct is_mpi_op<logical_xor<T>, T>
  : public boost::mpl::or_<is_mpi_integer_datatype<T>,
                           is_mpi_logical_datatype<T> >
{
  static MPI_Op op() { return MPI_LXOR; }
};

/// INTERNAL ONLY
template<typename T>
 struct is_mpi_op<bitwise_and<T>, T>
  : public boost::mpl::or_<is_mpi_integer_datatype<T>,
                           is_mpi_byte_datatype<T> >
{
  static MPI_Op op() { return MPI_BAND; }
};

/// INTERNAL ONLY
template<typename T>
 struct is_mpi_op<bitwise_or<T>, T>
  : public boost::mpl::or_<is_mpi_integer_datatype<T>,
                           is_mpi_byte_datatype<T> >
{
  static MPI_Op op() { return MPI_BOR; }
};

/// INTERNAL ONLY
template<typename T>
 struct is_mpi_op<bitwise_xor<T>, T>
  : public boost::mpl::or_<is_mpi_integer_datatype<T>,
                           is_mpi_byte_datatype<T> >
{
  static MPI_Op op() { return MPI_BXOR; }
};

namespace detail {
  // A helper class used to create user-defined MPI_Ops
  template<typename Op, typename T>
  class user_op
  {
  public:
    explicit user_op(Op& op)
    {
      BOOST_MPI_CHECK_RESULT(MPI_Op_create,
                             (&user_op<Op, T>::perform,
                              is_commutative<Op, T>::value,
                              &mpi_op));

      op_ptr = &op;
    }

    ~user_op()
    {
      if (std::uncaught_exception()) {
        // Ignore failure cases: there are obviously other problems
        // already, and we don't want to cause program termination if
        // MPI_Op_free fails.
        MPI_Op_free(&mpi_op);
      } else {
        BOOST_MPI_CHECK_RESULT(MPI_Op_free, (&mpi_op));
      }
    }

    MPI_Op& get_mpi_op()
    {
      return mpi_op;
    }

  private:
    MPI_Op mpi_op;
    static Op* op_ptr;

    static void BOOST_MPI_CALLING_CONVENTION perform(void* vinvec, void* voutvec, int* plen, MPI_Datatype*)
    {
      T* invec = static_cast<T*>(vinvec);
      T* outvec = static_cast<T*>(voutvec);
      std::transform(invec, invec + *plen, outvec, outvec, *op_ptr);
    }
  };

  template<typename Op, typename T> Op* user_op<Op, T>::op_ptr = 0;

} // end namespace detail

} } // end namespace boost::mpi

#endif // BOOST_MPI_GET_MPI_OP_HPP


code:
#ifndef LIVE_FREQUENCY_VALIDATOR_HPP__
#define LIVE_FREQUENCY_VALIDATOR_HPP__

#include <QObject>
#include <QRegExpValidator>

#include "Radio.hpp"

class Bands;
class FrequencyList_v2;
class QComboBox;
class QWidget;

//
// Class LiveFrequencyValidator
//
//	QLineEdit validator that controls input to an editable
//	QComboBox where the user can enter a valid band or a valid
//	frequency in megahetz.
//
// Collabrations
//
//	Implements the QRegExpValidator interface. Validates input
//	from the supplied QComboBox as either a valid frequency in
//	megahertz or a valid band as defined by the supplied column of
//	the supplied QAbstractItemModel.
//
class LiveFrequencyValidator final
  : public QRegExpValidator
{
  Q_OBJECT;

public:
  using Frequency = Radio::Frequency;

  LiveFrequencyValidator (QComboBox * combo_box // associated combo box
                          , Bands const * bands // bands model
                          , FrequencyList_v2 const * frequencies // working frequencies model
                          , Frequency const * nominal_frequency
                          , QWidget * parent = nullptr);

  State validate (QString& input, int& pos) const override;
  void fixup (QString& input) const override;

  Q_SIGNAL void valid (Frequency) const;

private:
  Bands const * bands_;
  FrequencyList_v2 const * frequencies_;
  Frequency const * nominal_frequency_;
  QComboBox * combo_box_;
};

#endif