42   return new Count(*
this);
 
Count & operator=(const Count &rhs)
 
Count statistical function. 
 
A base class for unary functions. 
 
This is an abstract class that models a query expression. 
 
UnaryFunction & operator=(const UnaryFunction &rhs)
 
Expression * clone() const 
It creates a new copy of this expression. 
 
Count statistical function. 
 
TE_DEFINE_VISITABLE Count(Expression *arg)
Constructor.