### IADeque

  A deque or double-ended queue is a sequence with restricted access. It is an ordered collection of elements with no key and no element equality. The elements are arranged so that each collection has a first and a last element, each element except the last has a next element, and each element but the first has a previous element. You can only add or remove the first or the last element.

  The type and value of the elements are irrelevant, and have no effect on the behavior of the collection.

### IADeque - Member Functions and Data by Group

### Constructors & Destructor

You can construct and destruct objects of this class.

~IADeque

      public:
      ~IADeque()

  Removes all elements from the collection. Destructors are called for all elements contained in the collection and for elements that have been constructed in advance.

  Side Effects

  All cursors of the collection become undefined.

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

IADeque

  You can construct and destruct objects of this class.

  Overload 1

      public:
      IADeque(INotifier&)

  Use this constructor to create a collection with support for notification.

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

  Overload 2

      protected:
      IADeque(IADeque < Element > const&)

  Constructs a collection. The collection is unbounded and is initially empty.
  Note: The collection constructor does not define whether any elements are constructed when the collection is constructed. For some classes, the element's default constructor may be invoked when the collection's constructor is invoked. This happens if a tabular or a diluted sequence implementation variant is used for a collection. The element's default constructor is used to allocate the required storage and initialize the elements. Therefore, a default constructor must be available for elements in such cases.

  Exception

  IOutOfMemory

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

  Overload 3

      protected:
      IADeque()

  The default constructor.

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

### Comparison

Use these members as comparison operators.

compare

      public:
      long
        compare( IADeque < Element > const&,
                 long ( * comparisonFunction ) ( Element const & ,
                 Element const & ) ) const

  Compares the collection with the given collection. Comparison yields <0 if the collection is less than the given collection, 0 if the collection is equal to the given collection, and >0 if the collection is greater than the given collection. Comparison is defined by the first pair of corresponding elements, in both collections, that are not equal. If such a pair exists, the collection with the greater element is the greater one. Otherwise, the collection with more elements is the greater one.
  Note:

  1. The given comparison function must return a result according to the following rules:
     >0
       if (element1 > element2)
     0
       if (element1 == element2)
     <0
       if (element1 < element2)
  2. For elements of type char*, compare() is not locale-sensitive by default. Because it uses strcmp() and not strcoll(), it compares the binary values representing the characters, and is not based on the LC_COLLATE category of the current locale. Its results are reliable only for code pages and character sets in which the collating sequence matches the sequence of binary representations. If you need a comparison based on the LC_COLLATE cateogory, then you must implement your own compare() function as described in Using Separate Functions in the Class Library User's Guide.

  Return Value

  Returns the result of the collection comparison.

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

### Miscellaneous

addAsFirst

  Adds the element to the collection as the first element in sequential order. Sets the cursor to the added element.

  Preconditions

  - The cursor must belong to the collection.
  - If the collection is bounded, (numberOfElements() < maxNumberOfElements()).

  Side Effects

  All cursors of this collection, except the given cursor, become undefined.

  Exceptions

  - IOutOfMemory
  - IFullException, if the collection is bounded
  - IKeyAlreadyExistsException, if the collection is bounded

  Overload 1

      public:
      virtual void addAsFirst(Element const&, ICursor&)

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

  Overload 2

      public:
      virtual void addAsFirst(Element const&)

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

addAsLast

  Adds the element to the collection as the last element in sequential order. Sets the cursor to the added element.

  Preconditions

  - The cursor must belong to the collection.
  - If the collection is bounded, (numberOfElements() < maxNumberOfElements()).

  Side Effects

  All cursors of this collection, except the given cursor, become undefined.

  Exceptions

  - ICursorInvalidException
  - IOutOfMemory
  - IFullException.

  Overload 1

      public:
      virtual void addAsLast(Element const&, ICursor&)

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

  Overload 2

      public:
      virtual void addAsLast(Element const&)

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

removeFirst

      public:
      virtual void removeFirst()

  Removes the first element from the collection. Element destructors are called as described in IACollection::removeAt.

  Precondition

  The collection must not be empty.

  Side Effects

  All cursors of this collection become undefined.

  Exception

  IEmptyException

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

removeLast

      public:
      virtual void removeLast()

  Removes the last element from the collection. Element destructors are called as described in IACollection::removeAt.

  Precondition

  The collection must not be empty.

  Side Effects

  All cursors of this collection become undefined.

  Exception

  IEmptyException

Supported Platforms

  Windows | OS/2 | AIX
  Yes | Yes | Yes

### IADeque - Inherited Member Functions and Data

#### Inherited Public Functions

  IARestrictedAccessCollection

  -     virtual ~IARestrictedAccessCollection()

  -     virtual bool add(Element const&)

  -     virtual bool add(Element const&, ICursor&)

  -     virtual void
          addAllFrom( IARestrictedAccessCollection < Element > const& )

  -     void adoptStreamer(IACollectionStreamer*)

  -     bool allElementsDo(IConstantApplicator < Element >&) const

  -     bool
          allElementsDo( IBoolean ( * applicatorFunction ) ( Element const&,
                         void * ) , void* additionalArgument = 0 ) const

  -     Element const& any() const

  -     Element const& anyElement() const

  -     virtual void
          copy( IARestrictedAccessCollection < Element > const& )

  -     INotifier& disableNotification()

  -     Element const& elementAt(ICursor const&) const

  -     Element const& elementAtPosition(IPosition) const

  -     INotifier& enableNotification(bool = true)

  -     Element const& first() const

  -     Element const& firstElement() const

  -     IARestrictedAccessCollection(INotifier&)

  -     bool isBounded() const

  -     bool isConsistent() const

  -     bool isEmpty() const

  -     bool isEnabledForNotification() const

  -     bool isFirst(ICursor const&) const

  -     bool isFirstAt(ICursor const&) const

  -     bool isFull() const

  -     bool isLast(ICursor const&) const

  -     bool isLastAt(ICursor const&) const

  -     Element const& last() const

  -     Element const& lastElement() const

  -     INumber maxNumberOfElements() const

  -     virtual ICursor* newCursor() const

  -     INotifier const& notifier() const

  -     INotifier& notifier()

  -     INotifier& notifyObservers(INotificationEvent const&)

  -     INumber numberOfElements() const

  -     virtual void operator <<=(IDataStream&)

  -     virtual void operator >>=(IDataStream&)

  -     operator INotifier &() const

  -     IPosition position(ICursor const&) const

  -     IPosition positionAt(ICursor const&) const

  -     virtual INumber removeAll()

  -     bool setToFirst(ICursor&) const

  -     bool setToLast(ICursor&) const

  -     bool setToNext(ICursor&) const

  -     void setToPosition(IPosition, ICursor&) const

  -     bool setToPrevious(ICursor&) const

#### Inherited Public Data

  - None

#### Inherited Protected Functions

  IACollectionBase

  -     ~IACollectionBase()

  -     static ICursorImpl& CrsrImplOf(ICursor& cursor)

  -     static ICursorImpl const& CrsrImplOf(ICursor const& cursor)

  -     IACollectionBase()

  -     IACollectionBase(IACollectionBase const&)

  -     static ICursor* InterfaceFor(ICursorImpl* cursor)

  IARestrictedAccessCollection

  -     IARestrictedAccessCollection()

  -     IARestrictedAccessCollection( IARestrictedAccessCollection < Element > const& )

  -     static Implementation&
          ImplOf( IARestrictedAccessCollection < Element > const& )

#### Inherited Protected Data

  - None