TaQLConstNodeRep).
Motivation
The envelope/letter idiom (aka counted referencing) is a nice means
to pass an object around by value, so to ensure that an object is deleted
in case of an exception.
Furthermore it makes copying an object very cheap and memory
management straightforward.
Member Description
explicit TaQLNodeRep (int nodeType) :itsCount(0), itsNodeType(nodeType)
Constructor for derived classes specifying the type.
static TaQLNodeRep* link (TaQLNodeRep* rep)
Increment the reference count.
static void unlink (TaQLNodeRep* rep)
Decrement the reference count.
Delete the letter if no more references.
Get the node type of the derived class.
Visit a node for tree traversal.
virtual void show (std::ostream& os) const = 0
Print the object in an ostream.
virtual void save (AipsIO& aio) const = 0
Save the object.
Check the data type string and return its standard form.
TaQLNodeRep (const TaQLNodeRep&)
TaQLNodeRep& operator= (const TaQLNodeRep&)
Letter objects cannot be copied.