Oracle® Fusion Middleware C++ API Reference for Oracle Coherence: WrapperCollections::AbstractWrapperCollection Class Reference

If this collection fits in the array with additional room then the element in the array immediately following the end of the collection is set to NULL. This can be useful in determining the length of this collection if the caller knows that the collection does not contain any NULL elements.

Parameters:

hao

an array in which to store the collection's contents

Returns:: a ObjectArray containing all the elements of the collection in the same order as returned by the collection's Iterator

See also:: Iterator

virtual bool

add (Object::Holder oh)

Add the given element to this collection.

Parameters:

the element to add

Returns:: true iff this collection was modified as a result of this operation

virtual bool

remove (Object::View v)

Remove the supplied element from this collection.

Parameters:

the element to remove

Returns:: true iff this collection was modified as a result of this operation

virtual bool

containsAll (Collection::View vc) const

Determine if this collection contains all elements from the supplied collection.

Parameters:

vCol

the collection of elements to test for containment

Returns:: true iff this collection contains all elements from the supplied collection

Exceptions:

coherence::lang::NullPointerException

if the specified collection is NULL

See also:: contains()

virtual bool

addAll (Collection::View vc)

Add all elements from the supplied collection to this collection.

Parameters:

vCol

the collection of elements to add

Returns:: true iff this collection was modified as a result of this operation

Exceptions:

coherence::lang::NullPointerException

if the specified collection is NULL

See also:: add()

virtual bool

removeAll (Collection::View vc)

Remove all instances of the elements in the supplied collection from this collection.

Upon completion, contains() on this collection will return false for all elements in the supplied collection.

Parameters:

vCol

the collection of elements to remove

Returns:: true iff this collection was modified as a result of this operation

Exceptions:

coherence::lang::NullPointerException

if the specified collection is NULL

See also:: remove()
contains()

virtual bool

retainAll (Collection::View vc)

Remove all elements from this collection that are not present in the supplied collection.

Parameters:

vCol

the collection of elements to retain

Returns:: true iff this collection was modified as a result of this operation.

Exceptions:

coherence::lang::NullPointerException

if the specified collection is NULL

See also:: remove()
contains()

virtual void

clear ()

Remove all elements from this collection.

virtual void

toStream (std::ostream &out) const

Output a human-readable description of this Object to the given stream.

coherence::lang::operator<<(std::ostream, Object::View) is defined and will call into the toStream method, to output Objects. If a managed String object is desired, the COH_TO_STRING macro can be used to build up a String from streamable contents.

 Object::View vKey   = ...
 Object::View vValue = ...
 std::cout << vKey << " = " << vValue << std::endl;

 String::Handle hs = COH_TO_STRING(vKey << " = " << vValue);

Parameters:

out

the stream used to output the description

virtual size32_t

hashCode () const

Return a hash code value for the Object.

This method is supported for the benefit of hash-based containers.

The general contract of hashCode is:

Whenever it is invoked on the same Object more than once during an execution of an application, the hashCode method must consistently return the same value, provided no information used in equals comparisons on the object is modified. This value need not remain consistent from one execution of an application to another execution of the same application.
If two Objects are equal according to the equals method, then calling the hashCode method on each of the two Objects must produce the same value.
It is not required that if two Objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct results. However, the programmer should be aware that producing distinct results for unequal objects may improve the performance of hash-based containers.

The default implementation is identity based.

Returns:: a hash code value for this Object

virtual bool

equals (Object::View v) const

virtual bool

isImmutable () const

Return true iff no further changes can be made to the Object, that would effect the outcome of a call to its equals method.

Except for Objects which are naturally immutable (such as String), being immutable generally implies that the Object is only referenced via const pointers or views. Objects which hold references to child Objects, may need to take the immutability of their children into account when determining their own immutability.

This extended check is not performed by the default implementation, but can be integrated into the immutability checks by overriding this method, as well as making use of MemberHandles to reference child Objects.

A typical derived implementation may look as follows:

 bool isImmutable() const
     {
     if (m_fImmutable) // check recorded state
         {
         return true; // already marked as immutable, avoid calculation
         }
     else if (Object::isImmutable()) // ensure shallow immutability
         {
         // ensure deep immutability
         if (m_child1->isImmutable() && m_child2->isImmutable() ...
                                     && m_childN->isImmutable())
             {
             // record and return immutability
             return m_fImmutable = true;
             }
         // some Objects which comprise this Object are still mutable
         }
     return false;
     }

The default implementation return true iff the Object is only referenced via const pointers and or views.