Tools.h++ Manual

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17
Virtual functions restoreGuts(RWFile&) and restoreGuts(RWvistream&)
In a similar manner to saveGuts() , these virtual functions are used to restore
the internal state of an RWCollectable from a file or stream. Here is a
definition for Bus :
Note how the pointer passengers_ is restored using
RWvistream& operator>>(RWvistream&, RWCollectable*&);
If the original passengers_ was non-nil, then this function will restore a new
RWSet off the heap and return a pointer to it. Otherwise, it will return a nil
pointer. Either way, the old contents of passengers_ will be replaced.
Hence, we must call " delete passengers_ " first.
Virtual function binaryStoreSize()
The virtual function
virtual RWspace binaryStoreSize() const;
void Bus::restoreGuts(RWFile& f)
{
RWCollectable::restoreGuts(f); // Restore base class
f.Read(busNumber_); // Restore primitive
f >> driver_ >> customers_; // Uses Tools.h++ provided
versions
delete passengers_; // Delete old RWSet
f >> passengers_; // Replace with a new one
}
void Bus::restoreGuts(RWvistream& strm)
{
RWCollectable::restoreGuts(strm);// Restore base class
strm >> busNumber_ >> driver_ >> customers_;
delete passengers_; // Delete old RWSet
strm >> passengers_; // Replace with a new one
}