EOL;
        $key_type = 'Key';
        $key_name = 'key';
        $value_type = 'std::pair<Key const, Mapped>';
        $full_type = $name.'<Key, Mapped, Hash, Pred, Alloc>';
    }
    else
    {
        $template_value = <<
            
EOL;
        $key_type = 'Value';
        $key_name = 'value';
        $value_type = 'Value';
        $full_type = $name.'<Value, Hash, Pred, Alloc>';
    }
?>
        
          
            
              boost::hash<>
            
            
              std::equal_to<>
            
            
              std::allocator<>
            
          
          
            An unordered associative container that 
          
          
            Template Parameters
              
                
                  
                    
                      Key
                      Key must be Erasable from the container
                        (i.e. allocator_traits can destroy it).
                      
                    
                      Mapped
                      Mapped must be Erasable from the container
                        (i.e. allocator_traits can destroy it).
                      
                    
                      Value
                      Value must be Erasable from the container
                        (i.e. allocator_traits can destroy it).
                      
                    
                      Hash
                      A unary function object type that acts a hash function for a 
                    
                      Pred
                      A binary function object that implements an equivalence relation on values of type 
                    
                      Alloc
                      An allocator whose value type is the same as the container's value type.
            The elements are organized into buckets. 
            The number of buckets can be automatically increased by a call to insert, or as the result of calling rehash.
          
          
            
          
          
            
          
          
            Mapped
          
          
            Hash
          
          
            Pred
          
          
            Alloc
          
          
            typename allocator_type::pointer
            
              
                value_type* if
                allocator_type::pointer is not defined.
              
            
          
          
            typename allocator_type::const_pointer
            
              
                boost::pointer_to_other<pointer, value_type>::type
                if allocator_type::const_pointer is not defined.
              
            
          
          
            value_type&
            lvalue of value_type.
          
          
            value_type const&
            const lvalue of value_type.
          
          
            implementation-defined
            
              An unsigned integral type.
              size_type can represent any non-negative value of difference_type.
            
          
          
            implementation-defined
            
              A signed integral type.
              Is identical to the difference type of iterator and const_iterator.
            
          
          
            implementation-defined
            
               iterator whose value type is value_type. 
              The iterator category is at least a forward iterator.
              Convertible to const_iterator.
            
          
          
            implementation-defined
            
              A constant iterator whose value type is value_type. 
              The iterator category is at least a forward iterator.
            
          
          
            implementation-defined
            
              An iterator with the same value type, difference type and pointer and reference type as iterator.
              A local_iterator object can be used to iterate through a single bucket.
            
          
          
            implementation-defined
            
              A constant iterator with the same value type, difference type and pointer and reference type as const_iterator.
              A const_local_iterator object can be used to iterate through a single bucket.
            
          
          
            implementation-defined
            
              See node_handle_ for details.
            
          
          
            implementation-defined
            
              Structure returned by inserting node_type.
            
          
          
            
              size() == 0
            
            
              Constructs an empty container using hasher() as the hash function, key_equal() as the key equality predicate, allocator_type() as the allocator and a maximum load factor of 1.0.
            
            
              If the defaults are used, hasher, key_equal and
                allocator_type need to be DefaultConstructible.
              
            
          
          
            
              size_type
            
            
              hasher const&
              hasher()
            
            
              key_equal const&
              key_equal()
            
            
              allocator_type const&
              allocator_type()
            
            
              size() == 0
            
            
              Constructs an empty container with at least n buckets, using hf as the hash function, eq as the key equality predicate, a as the allocator and a maximum load factor of 1.0.
            
            
              If the defaults are used, hasher, key_equal and
                allocator_type need to be DefaultConstructible.
              
            
          
          
            
              
              
            
            
              InputIterator
            
            
              InputIterator
            
            
              size_type
              implementation-defined
            
            
              hasher const&
              hasher()
            
            
              key_equal const&
              key_equal()
            
            
              allocator_type const&
              allocator_type()
            
            
              Constructs an empty container with at least n buckets,
              using hf as the hash function,
              eq as the key equality predicate,
              a as the allocator and a maximum load factor of 1.0
              and inserts the elements from [f, l) into it.
              
            
            
              If the defaults are used, hasher, key_equal and
                allocator_type need to be DefaultConstructible.
              
            
          
          
            
               const&
            
            
              The copy constructor. Copies the contained elements, hash function, predicate, maximum load factor and allocator.
              If Allocator::select_on_container_copy_construction
              exists and has the right signature, the allocator will be
              constructed from its result.
            
            
              value_type is copy constructible
            
          
          
            
               &&
            
            
              The move constructor.
            
            
              This is implemented using Boost.Move.
            
            
              
                value_type is move constructible.
              
              
                On compilers without rvalue reference support the
                emulation does not support moving without calling
                boost::move if value_type is
                not copyable. So, for example, you can't return the
                container from a function.
              
            
          
          
            
              Allocator const&
            
            
                Constructs an empty container, using allocator a.
            
          
          
            
               const&
            
            
              Allocator const&
            
            
                Constructs an container, copying x's contained elements, hash function, predicate, maximum load factor, but using allocator a.
            
          
          
            
               &&
            
            
              Allocator const&
            
            
              Construct a container moving x's contained elements, and having the hash function, predicate and maximum load factor, but using allocate a.
            
            
              This is implemented using Boost.Move.
            
            
              
                value_type is move insertable.
              
            
          
          
            
              initializer_list<value_type>
            
            
              size_type
              implementation-defined
            
            
              hasher const&
              hasher()
            
            
              key_equal const&
              key_equal()
            
            
              allocator_type const&
              allocator_type()
            
            
              Constructs an empty container with at least n buckets,
                using hf as the hash function,
                eq as the key equality predicate,
                a as the allocator and a maximum load factor of 1.0
                and inserts the elements from il into it.
              
            
            
              If the defaults are used, hasher, key_equal and
                allocator_type need to be DefaultConstructible.
              
            
          
          
            
              size_type
            
            
              allocator_type const&
            
            
              size() == 0
            
            
              Constructs an empty container with at least n buckets,
              using hf as the hash function,
              the default hash function and key equality predicate,
              a as the allocator and a maximum load factor of 1.0.
            
            
              hasher and key_equal need to be DefaultConstructible.
              
            
          
          
            
              size_type
            
            
              hasher const&
            
            
              allocator_type const&
            
            
              size() == 0
            
            
              Constructs an empty container with at least n buckets,
              using hf as the hash function,
              the default key equality predicate,
              a as the allocator and a maximum load factor of 1.0.
            
            
              key_equal needs to be DefaultConstructible.
              
            
          
          
            
              
              
            
            
              InputIterator
            
            
              InputIterator
            
            
              size_type
            
            
              allocator_type const&
            
            
              Constructs an empty container with at least n buckets,
              using  a as the allocator, with the
              default hash function and key equality predicate
              and a maximum load factor of 1.0
              and inserts the elements from [f, l) into it.
              
            
            
              hasher, key_equal need to be DefaultConstructible.
              
            
          
          
            
              
              
            
            
              InputIterator
            
            
              InputIterator
            
            
              size_type
            
            
              hasher const&
            
            
              allocator_type const&
            
            
              Constructs an empty container with at least n buckets,
              using hf as the hash function,
              a as the allocator, with the
              default key equality predicate
              and a maximum load factor of 1.0
              and inserts the elements from [f, l) into it.
              
            
            
              key_equal needs to be DefaultConstructible.
              
            
          
          
            
              The destructor is applied to every element, and all memory is deallocated
            
          
          
            
               const&
            
            &
            
              The assignment operator. Copies the contained elements, hash function, predicate and maximum load factor but not the allocator.
              If Alloc::propagate_on_container_copy_assignment
              exists and Alloc::propagate_on_container_copy_assignment::value
               is true, the allocator is overwritten, if not the
              copied elements are created using the existing
              allocator.
            
            
              value_type is copy constructible
            
          
          
            
               &&
            
            &
            
              The move assignment operator.
              If Alloc::propagate_on_container_move_assignment
              exists and Alloc::propagate_on_container_move_assignment::value
               is true, the allocator is overwritten, if not the
              moved elements are created using the existing
              allocator.
            
            
              
                On compilers without rvalue references, this is emulated using
                Boost.Move. Note that on some compilers the copy assignment
                operator may be used in some circumstances.
              
            
            
              
                value_type is move constructible.
              
            
          
          
            
              initializer_list<value_type>
            
            &
            
              Assign from values in initializer list. All existing elements are either overwritten by the new elements or destroyed.
            
            
              
                value_type is CopyInsertable into the container and
                CopyAssignable.
              
            
          
          
            allocator_type
          
          
            
              bool
              
                size() == 0
              
            
            
              size_type
              
                std::distance(begin(), end())
              
            
            
              size_type
              size() of the largest possible container.
              
            
          
          
            
              iterator
              const_iterator
              An iterator referring to the first element of the container, or if the container is empty the past-the-end value for the container.
              
            
            
              
                iterator
              
              
                const_iterator
              
              An iterator which refers to the past-the-end value for the container.
              
            
            
              const_iterator
              A constant iterator referring to the first element of the container, or if the container is empty the past-the-end value for the container.
              
            
            
              const_iterator
              A constant iterator which refers to the past-the-end value for the container.
              
            
          
          
            
              
                
                
              
              
                Args&&
              
              
              
                Inserts an object, constructed with the arguments args, in the container
              
              
                value_type is EmplaceConstructible into
                  X from args.
                
              
              
                An iterator pointing to the inserted element.
                The bool component of the return type is true if an insert took place.
                If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent .
              
              
                If an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
                If the compiler doesn't support variadic template arguments or rvalue
                      references, this is emulated for up to 10 arguments, with no support
                      for rvalue references or move semantics.
                Since existing std::pair implementations don't support
                      std::piecewise_construct this emulates it,
                      but using boost::unordered::piecewise_construct.
              
            
            
              
                
                
              
              
                const_iterator
              
              
                Args&&
              
              iterator
              
                Inserts an object, constructed with the arguments args, in the container
                hint is a suggestion to where the element should be inserted.
              
              
                value_type is EmplaceConstructible into
                  X from args.
                
              
              
                An iterator pointing to the inserted element.
                If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent .
              
              
                If an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                The standard is fairly vague on the meaning of the hint. But the only practical way to use it, and the only way that Boost.Unordered supports is to point to an existing element with the same . 
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
                If the compiler doesn't support variadic template arguments or rvalue
                      references, this is emulated for up to 10 arguments, with no support
                      for rvalue references or move semantics.
                Since existing std::pair implementations don't support
                      std::piecewise_construct this emulates it,
                      but using boost::unordered::piecewise_construct.
              
            
            
              
                value_type const&
              
              
              
                Inserts obj in the container
              
              
                value_type is CopyInsertable.
              
              
                An iterator pointing to the inserted element.
                The bool component of the return type is true if an insert took place.
                If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent .
              
              
                If an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
              
            
            
              
                value_type&&
              
              
              
                Inserts obj in the container
              
              
                value_type is MoveInsertable.
              
              
                An iterator pointing to the inserted element.
                The bool component of the return type is true if an insert took place.
                If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent .
              
              
                If an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
              
            
            
              
                const_iterator
              
              
                value_type const&
              
              iterator
              
                Inserts obj in the container.
                Inserts obj in the container if and only if there is no element in the container with an equivalent .
                hint is a suggestion to where the element should be inserted.
              
              
                value_type is CopyInsertable.
              
              
                An iterator pointing to the inserted element.
                If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent .
              
              
                If an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                The standard is fairly vague on the meaning of the hint. But the only practical way to use it, and the only way that Boost.Unordered supports is to point to an existing element with the same . 
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
              
            
            
              
                const_iterator
              
              
                value_type&&
              
              iterator
              
                Inserts obj in the container.
                Inserts obj in the container if and only if there is no element in the container with an equivalent .
                hint is a suggestion to where the element should be inserted.
              
              
                value_type is MoveInsertable.
              
              
                An iterator pointing to the inserted element.
                If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent .
              
              
                If an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                The standard is fairly vague on the meaning of the hint. But the only practical way to use it, and the only way that Boost.Unordered supports is to point to an existing element with the same . 
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
              
            
            
              
                
                
              
              
                InputIterator
              
              
                InputIterator
              
              void
              
                Inserts a range of elements into the container.
                Elements are inserted if and only if there is no element in the container with an equivalent .
                
              
              
                value_type is EmplaceConstructible into
                  X from *first.
              
              
                When inserting a single element, if an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
              
            
            
              
                initializer_list<value_type>
              
              void
              
                Inserts a range of elements into the container.
                
                Elements are inserted if and only if there is no element in the container with an equivalent .
                
                
              
              
                value_type is EmplaceConstructible into
                  X from *first.
              
              
                When inserting a single element, if an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
              
            
            
              
                initializer_list<value_type>
              
              void
              
                Inserts a range of elements into the container. Elements are inserted if and only if there is no element in the container with an equivalent .
              
              
                value_type is EmplaceConstructible into
                  X from *first.
              
              
                When inserting a single element, if an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
              
            
            
              
                const_iterator
              
              node_type
              
                Removes the element pointed to by position.
              
              
                A node_type owning the element.
              
              
                
                  In C++17 a node extracted using this method can be inserted into a compatible k.
              
              
                A node_type owning the element if found, otherwise an empty node_type.
              
              
                Only throws an exception if it is thrown by hasher or key_equal.
              
              
                
                  In C++17 a node extracted using this method can be inserted into a compatible nh is empty, has no affect.
                Otherwise inserts the element owned by nh
                Otherwise inserts the element owned by nh
                      if and only if there is no element in the container with an equivalent .
                
              
              
                nh is empty or nh.get_allocator() is equal to the container's allocator.
              
              
                If nh was empty, returns end().
                Otherwise returns an iterator pointing to the newly inserted element.
                If nh was empty, returns an insert_return_type with:
                      inserted equal to false,
                      position equal to end() and
                      node empty.
                Otherwise if there was already an element with an equivalent key, returns an insert_return_type with:
                      inserted equal to false,
                      position pointing to a matching element and
                      node contains the node from nh.
                Otherwise if the insertion succeeded, returns an insert_return_type with:
                      inserted equal to true,
                      position pointing to the newly inserted element and
                      node empty.
              
              
                If an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
                In C++17 this can be used to insert a node extracted from a compatible nh is empty, has no affect.
                Otherwise inserts the element owned by nh
                Otherwise inserts the element owned by nh
                      if and only if there is no element in the container with an equivalent .
                
                If there is already an element in the container with an equivalent 
                      has no effect on nh (i.e. nh still contains the node.)
                hint is a suggestion to where the element should be inserted.
              
              
                nh is empty or nh.get_allocator() is equal to the container's allocator.
              
              
                If nh was empty, returns end().
                Otherwise returns an iterator pointing to the newly inserted element.
                If nh was empty returns end().
                If there was already an element in the container with an equivalent 
                      returns an iterator pointing to that.
                Otherwise returns an iterator pointing to the newly inserted element.
              
              
                If an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                The standard is fairly vague on the meaning of the hint. But the only practical way to use it, and the only way that Boost.Unordered supports is to point to an existing element with the same . 
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
                In C++17 this can be used to insert a node extracted from a compatible position.
              
              
                The iterator following position before the erasure.
              
              
                Only throws an exception if it is thrown by hasher or key_equal.
              
              
                
                  In older versions this could be inefficient because it had to search
                  through several buckets to find the position of the returned iterator.
                  The data structure has been changed so that this is no longer the case,
                  and the alternative erase methods have been deprecated.
                
              
            
            
              
                key_type const&
              
              size_type
              
                Erase all elements with key equivalent to k.
              
              
                The number of elements erased.
              
              
                Only throws an exception if it is thrown by hasher or key_equal.
              
            
            
              
                const_iterator
              
              
                const_iterator
              
              iterator
              
                Erases the elements in the range from first to last.
              
              
                The iterator following the erased elements - i.e. last.
              
              
                Only throws an exception if it is thrown by hasher or key_equal.
                In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
              
            
            
              
                const_iterator
              
              void
              
                Erase the element pointed to by position.
              
              
                Only throws an exception if it is thrown by hasher or key_equal.
                In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
              
              
                
                  This method was implemented because returning an iterator to
                  the next element from erase was expensive, but
                  the container has been redesigned so that is no longer the
                  case. So this method is now deprecated.
                
              
            
            
              
                const_iterator
              
              void
              
                Erase the element pointed to by position.
              
              
                Only throws an exception if it is thrown by hasher or key_equal.
                In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
              
              
                
                  This method was implemented because returning an iterator to
                  the next element from erase was expensive, but
                  the container has been redesigned so that is no longer the
                  case. So this method is now deprecated.
                
              
            
            
              void
              
                Erases all elements in the container.
              
              
                size() == 0
              
              
                Never throws an exception.
              
            
            
              
                &
              
              void
              
                Swaps the contents of the container with the parameter.
                If Allocator::propagate_on_container_swap is declared and
                  Allocator::propagate_on_container_swap::value is true then the
                  containers' allocators are swapped. Otherwise, swapping with unequal allocators
                  results in undefined behavior.
              
              
                Doesn't throw an exception unless it is thrown by the copy constructor or copy assignment operator of key_equal or hasher.
              
              
                The exception specifications aren't quite the same as the C++11 standard, as
                  the equality predieate and hash function are swapped using their copy constructors.
              
            
            
              
                
                
                
                
              
              
                <Key, Mapped, H2, P2, Alloc>&
                <Value, H2, P2, Alloc>&
              
              
                Does not support merging with a compatible k, or b.end() if no such element exists.
              
              
                The templated overloads are a non-standard extensions which
                allows you to use a compatible hash function and equality
                predicate for a key of a different type in order to avoid
                an expensive type cast. In general, its use is not encouraged.
              
            
            
              
                key_type const&
              
              size_type
              
                The number of elements with key equivalent to k.
              
            
            
              
                
                  key_type const&
                
                std::pair<iterator, iterator>
              
              
                
                  key_type const&
                
                std::pair<const_iterator, const_iterator>
              
              
                A range containing all elements with key equivalent to k.
                  If the container doesn't container any such elements, returns
                  std::make_pair(b.end(),b.end()).
                  
              
            
            
              
                key_type const&
              
              mapped_type&
              
                If the container does not already contain an elements with a key equivalent to k, inserts the value std::pair<key_type const, mapped_type>(k, mapped_type())
              
              
                A reference to x.second where x is the element already in the container, or the newly inserted element with a key equivalent to k
              
              
                If an exception is thrown by an operation other than a call to hasher the function has no effect.
              
              
                Can invalidate iterators, but only if the insert causes the load factor to be greater to or equal to the maximum load factor.
                Pointers and references to elements are never invalidated.
              
            
            
              Mapped&
                key_type const&
              Mapped const&
                key_type const&
              
                A reference to x.second where x is the (unique) element whose key is equivalent to k.
              
              
                An exception object of type std::out_of_range if no such element is present.
              
            
          
          
            
              size_type
              
                The number of buckets.
              
            
            
              size_type
              
                An upper bound on the number of buckets.
              
            
            
              
                size_type
              
              size_type
              
                n < bucket_count()
              
              
                The number of elements in bucket n.
              
            
            
              
                key_type const&
              
              size_type
              
                The index of the bucket which would contain an element with key k.
              
              
                The return value is less than bucket_count()
              
            
            
              
                
                  size_type
                
                local_iterator
              
              
                
                  size_type
                
                const_local_iterator
              
              
                n shall be in the range [0, bucket_count()).
              
              
                A local iterator pointing the first element in the bucket with index n.
              
            
            
              
                
                  size_type
                
                local_iterator
              
              
                
                  size_type
                
                const_local_iterator
              
              
                n shall be in the range [0, bucket_count()).
              
              
                A local iterator pointing the 'one past the end' element in the bucket with index n.
              
            
            
              
                size_type
              
              const_local_iterator
              
                n shall be in the range [0, bucket_count()).
              
              
                A constant local iterator pointing the first element in the bucket with index n.
              
            
            
              
                size_type
              
              const_local_iterator
              
                n shall be in the range [0, bucket_count()).
              
              
                A constant local iterator pointing the 'one past the end' element in the bucket with index n.
              
            
          
          
            
              float
              
                The average number of elements per bucket.
              
            
            
              float
              
                Returns the current maximum load factor.
              
            
            
              
                float
              
              void
              
                Changes the container's maximum load factor, using z as a hint.
              
            
            
              
                size_type
              
              void
              
                Changes the number of buckets so that there at least n buckets, and so that the load factor is less than the maximum load factor.
                Invalidates iterators, and changes the order of elements. Pointers and references to elements are not invalidated.
              
              
                The function has no effect if an exception is thrown, unless it is thrown by the container's hash function or comparison function.
              
            
            
              
                size_type
              
              void
              
                Invalidates iterators, and changes the order of elements. Pointers and references to elements are not invalidated.
              
              
                The function has no effect if an exception is thrown, unless it is thrown by the container's hash function or comparison function.
              
            
          
          
            
              
                
                
                
                
                
                
              
              
                 const&
              
              
                 const&
              
              bool
              
                Return true if x.size() ==
                y.size and for every equivalent key group in
                x, there is a group in y
                for the same key, which is a permutation (using
                operator== to compare the value types).
                
                Return true if x.size() ==
                y.size and for every element in x,
                there is an element in y with the same
                for the same key, with an equal value (using
                operator== to compare the value types).
                
              
              
                The behavior of this function was changed to match
                  the C++11 standard in Boost 1.48.
                Behavior is undefined if the two containers don't have
                    equivalent equality predicates.
              
            
            
              
                
                
                
                
                
                
              
              
                 const&
              
              
                 const&
              
              bool
              
                Return false if x.size() ==
                y.size and for every equivalent key group in
                x, there is a group in y
                for the same key, which is a permutation (using
                operator== to compare the value types).
                
                Return false if x.size() ==
                y.size and for every element in x,
                there is an element in y with the same
                for the same key, with an equal value (using
                operator== to compare the value types).
                
              
              
                The behavior of this function was changed to match
                  the C++11 standard in Boost 1.48.
                Behavior is undefined if the two containers don't have
                    equivalent equality predicates.
              
            
          
          
            
              
                
                
                
                
                
                
              
              
                &
              
              
                &
              
              void
              
                x.swap(y)
              
              
                Swaps the contents of x and y.
                If Allocator::propagate_on_container_swap is declared and
                  Allocator::propagate_on_container_swap::value is true then the
                  containers' allocators are swapped. Otherwise, swapping with unequal allocators
                  results in undefined behavior.
              
              
                Doesn't throw an exception unless it is thrown by the copy constructor or copy assignment operator of key_equal or hasher.
              
              
                The exception specifications aren't quite the same as the C++11 standard, as
                  the equality predieate and hash function are swapped using their copy constructors.
              
            
          
        
      
        
          
            
          
          
            
              An object that owns a single element extracted from an
              unordered_ or an
              unordered_multi, that
              can then be inserted into a compatible container type.
            
            
              
                The name and template parameters of this type is implementation
                defined, and should be obtained using the node_type
                member typedef from the appropriate container.
              
              
                In this version of Boost, node_type is different
                for unordered_map and unordered_multimap,' :
                  'unordered_set and unordered_multiset,';
                ?> this will be fixed in a future version of Boost.
              
            
          
          
            typename Container::key_type
          
          
            typename Container::mapped_type
          
          
            typename Container::value_type>
          
          
            typename Container::allocator_type>
          
          
          
          
          
            
               &&
            
          
          
            
              &&
            
            &
          
          
            key_type&
          
          
            mapped_type&
          
          
            value_type&
          
          
            allocator_type
          
          
          
          
            bool
          
          
            
              &
            
            void
            
              
                In C++17 is also noexcept if ator_traits::is_always_equal::value is true.
                But we don't support that trait yet.
              
            
          
          
            
              
                
              
              
                &
              
              
                &
              
              void
              
                x.swap(y)