Class TSwizzleCBase

TSwizzleCBase

Support

Supported from 5.0

Description

Base class for swizzles.

A swizzle maintains a dual representation for an object:

• by stream id, if the object is not in memory (the stream contains the external representation of that object).

• by pointer, if the object is in memory.

The class is not intended for instantiation.

Defined in TSwizzleCBase:
AsId(), InternalizeL(), IsId(), IsPtr(), operator!=(), operator==()

TBool IsPtr() const;

Description

Tests whether this swizzle currently represents an object as a pointer.

Return value

TBool True, if this swizzle currently maintains the object representation as a pointer; False, otherwise. Note that if the swizzle is uninitialised, the value returned by this function is not defined.

TBool IsId() const;

Description

Tests whether this swizzle currently represents an object as a stream id.

Return value

TBool True, if this swizzle currently maintains the representation of the object as a stream id; False, otherwise. Note that if the swizzle is uninitialised, the value returned by this function is not defined.

TStreamId AsId() const;

Description

Returns the streamid of the represented object.

This swizzle must currently represent the object as a stream id, otherwise the function raises a STORE-Store 3 panic.

Return value

TStreamId The stream id of the represented object

void InternalizeL(RReadStream& aStream);

Description

Internalises a stream id from the read stream, constructs a swizzle from this stream id and copies the swizzle to this swizzle.

The presence of this function means that the standard templated operator>>() can be used to internalise objects of this class.

Parameters

RReadStream& aStream Stream from which the stream id should be internalised

TBool operator==(const TSwizzleCBase& aSwizzle) const;

Description

Compare for equality with another swizzle.

Use this operator to determine whether this swizzle represents the same object as that represented by the specified swizzle.

Both this swizzle and the specified swizzle must maintain the representation of their respective objects as either pointers or stream ids.

If one swizzle maintains the representation of its object as a pointer while the other swizzle maintains the representation of its object as a stream id, the comparison is meaningless and always returns false.

Parameters

const TSwizzleCBase& aSwizzle A reference to the swizzle to be compared with this swizzle.

Return value

TBool True, if the represented objects are the same; False, otherwise.

TBool operator==(const TAny* aPtr) const;

Description

Compare for equality with an in-memory object.

Use this operator to determine whether this swizzle represents the same in-memory object as that represented by the specified pointer.

This swizzle must maintain the representation of its object as a pointer. If it maintains the representation of its object as a swizzle, the comparison is meaningless and always returns false.

Parameters

const TAny* aPtr A pointer to the object to be compared with this swizzle.

Return value

TBool True, if the represented objects are the same; False, otherwise.

TBool operator!=(const TSwizzleCBase& aSwizzle) const;

Description

Compare for inequality with another swizzle.

Use this operator to determine whether this swizzle represents a different object to that represented by the specified swizzle.

Both this swizzle and the specified swizzle must maintain the representation of their respective objects as either pointers or stream ids.

If one swizzle maintains the representation of its object as a pointer while the other swizzle maintains the representation of its object as a stream id, the comparison is meaningless and always returns true.

Parameters

const TSwizzleCBase& aSwizzle A reference to the swizzle to be compared with this swizzle.

Return value

TBool True, if the represented objects are not the same; False, otherwise

TBool operator!=(const TAny* aPtr) const;

Description

Compare for inequality with an in-memory object.

Use this operator to determine whether this swizzle represents a different in-memory object to that represented by the specified pointer.

This swizzle must maintain the representation of its object as a pointer. If it maintains the representation of its object as a swizzle, the comparison is meaningless and always returns true.

Parameters

const TAny* aPtr A pointer to the object to be compared with this swizzle.

Return value

TBool True, if the represented objects are not the same; False, otherwise