GPL_Reference

gpl

1998 12-05

CLASS

SYNOPSIS

CONSTRUCTORS

GPL_Reference(void)
Sets up a null-reference.



GPL_Reference(const GPL_Reference & ref)
Attach this reference to ref, via Attach(ref).

OPERATORS

GPL_Reference & operator=(const GPL_Reference & ref)
Assign the reference ref to this reference. This is a shallow copy. Return this reference.

MEMBER FUNCTIONS

GPL_Boolean IsValid(void) const
Return TRUE if the reference is valid (not null).



GPL_Boolean IsShared(void) const
Return TRUE if the reference shares its representation with at least one other reference.



void Attach(const GPL_Reference & ref)
Makes this reference use the same representation as ref. This increments the reference count by one.



void Detach(void)
Makes this reference a null reference by clearing its representation. This decrements the reference count by one and, if this is the last reference to the data, frees the memory for the representation. This works because sub-classes have derived their representations from GPL_Reference::Rep, whose destructor is virtual, and provided their own destructor.



virtual void Privatize(void)
Makes this reference use a private copy of the data. If the representation is shared, it makes a private copy using the copy constructor of GPL_Reference::Rep. Sub-classes that have extended GPL_Reference::Rep or want different behavior, should provide their own version of this method. Well-behaved classes invoke this method prior to any alteration of the shared representation.

MACROS