Class: TRecordFieldHandle

Declaration: Record.h

Taxonomy Categories:

Member Functions:

Interface Category:

API.

Inherits From:

None.

Inherited By:

TRecordDoubleFieldHandle TRecordFieldHandleOf TRecordLongFieldHandle TRecordShortFieldHandle TRecordUnsignedCharFieldHandle

Purpose:

This concrete class is a counted pointer memory management surrogate for record fields. That is, it helps manage the destruction of the record instance containing the field. Records are deleted when there are no record handles or field handles that reference the record.

Instantiation:

Always allocate on the stack.

Deriving Classes:

None.

Concurrency:

Not multithread safe.

Resource Use:

No special requirements.

Other Considerations:

None.

Member Function: TRecordFieldHandle::TRecordFieldHandle

TRecordFieldHandle ()
TRecordFieldHandle (const TRecordFieldHandle &)
TRecordFieldHandle (TRecord * record, const TRecordField & field)

Interface Category:

API.

Purpose:

Default constructor. Returns a handle to a field whose value is null, and belongs to the null record.
Copy constructor.
Special constructor used by TRecord to attach a field handle to a field of a record. Providers and clients need not use this member function.

Calling Context:

Called by the stream-in operators and any other function that needs to construct an uninitialized object.
Called to copy an object.
Call this function directly.

Parameters:

Takes no parameters.
const TRecordFieldHandle & -The handle to be copied.
TRecord * record -The master object.
const TRecordField & field -The target field.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRecordFieldHandle::operator=

TRecordFieldHandle & operator =(const TRecordFieldHandle &)

Interface Category:

API.

Purpose:

Assignment operator.

Calling Context:

Called when an object is assigned to another compatible object.

Parameters:

const TRecordFieldHandle & -The handle to copy.

Return Value:

A non-const reference to the left-hand side object.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRecordFieldHandle::~TRecordFieldHandle

~ TRecordFieldHandle ()

Interface Category:

API.

Purpose:

Destructor.

Calling Context:

Called to destroy an object.

Parameters:

Takes no parameters.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRecordFieldHandle::Name

virtual const ClassName & Name () const

Interface Category:

API.

Purpose:

Returns the class name of the associated field.

Calling Context:

Call this function directly.

Parameters:

Takes no parameters.

Return Value:

The class name of the associated field.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRecordFieldHandle::DescendsFrom

virtual bool DescendsFrom (const ClassName & className) const

Interface Category:

API.

Purpose:

Determines if the associated field descends from the named TRecordField class.

Calling Context:

Call this function directly.

Parameters:

const ClassName & className -The class name to check against.

Return Value:

Returns true if the associated field descends from the named TRecordField class.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRecordFieldHandle::operator==

virtual bool operator ==(const TRecordFieldHandle &) const

Interface Category:

API.

Purpose:

Determines if this handle is equivalent to its argument.

Calling Context:

Called to test equivalence of two objects.

Parameters:

const TRecordFieldHandle & -The handle to compare with this object.

Return Value:

Returns true if both handles share the same master.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRecordFieldHandle::operator!=

virtual bool operator != (const TRecordFieldHandle &) const

Interface Category:

API.

Purpose:

Determines if this handle is not equivalent to its argument.

Calling Context:

Called to test equivalence of two objects.

Parameters:

const TRecordFieldHandle & -The handle to compare with this object.

Return Value:

Returns true if both handles do not share the same master.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRecordFieldHandle::IsNull

virtual bool IsNull () const

Interface Category:

API.

Purpose:

Determines if this field is null, that is, has no value.

Calling Context:

Call this function directly.

Parameters:

Takes no parameters.

Return Value:

Returns true if this field is null.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRecordFieldHandle::Replace

virtual void Replace (const TRecordFieldHandle &)

Interface Category:

API.

Purpose:

Replaces this field with a copy of its argument.

Calling Context:

Call this function directly.

Parameters:

const TRecordFieldHandle & -The source field handle.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRecordFieldHandle::MakeNull

virtual void MakeNull ()

Interface Category:

API.

Purpose:

Assigns null to this field.

Calling Context:

Call this function directly.

Parameters:

Takes no parameters.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

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