HP Integrity NonStop J-Series - Manual (Page 217)

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©Copyright 1996 Rogue Wave Software
How to Create an RWCollectable Object
Here's an outline of how to make your object inherit from RWCollectable . Additional information
about how to do each step appears in the indicated section.
Define a default constructor. See below ( Define a Default... ) . 1.
Add the macro RWDECLARE_COLLECTABLE to your class declaration. See below ( Add
RWDECLARE_... ) .
2.
Provide a class identifier for your class by adding one of two definition macros,
RWDEFINE_COLLECTABLE or RWDEFINE_NAMED_COLLECTABLE, to one and
only one source file (.cpp), to be compiled.
See below ( Provide a Class Ident... ) .
3.
Add definitions for inherited virtual functions as necessary. You may be able to use inherited
definitions. The following virtual functions are dicussed
below ( Add Definitions... ) :
Int compareTo(const RWCollectable*) const;
RWBoolean isEqual(const RWCollectable*) const;
unsigned hash() const;
4.
Consider whether you need to define a destructor. See below ( Object Destruction ) . 5.
Add persistence to the class. You may be able to use inherited definitions, or you may have
to add definitions for the following functions.
See below ( How to add... ) .
RWspace binaryStoreSize() const;
void restoreGuts(RWFile&);
void restoreGuts(RWvistream&);
void saveGuts(RWFile&) const;
void saveGuts(RWvostream&) const;
6.
A note on RWFactory follows these steps. See below ( A Note on the RWFactory ) .
Define a Default Constructor
All RWCollectable classes must have a default constructor. The default constructor takes no
arguments. The persistence mechanism uses this constructor to create an empty object, then restore
that object with appropriate contents.