I posted this in the C++ forum, but decided to repost here as it relates to software development, and this might be a better audience for it.
I'm trying to implement a Visitor Pattern in c++, but I'm having problems with the elements being visited in turn having their children visited. For example I have a class Element, which has a vector of Nodes (can be elements or any classes that inherit from node):
class Element : public Node{
public:
Element();
Element(string n, string v = " ");
~Element();
void Accept(Visitor& v);
vector<Node*> nodeVec;
vector<Attr*> attrVec;
private:
string name, value;
};
void Element::Accept(Visitor& v)
{
v.VisitElement(*this);
}
And I have a concreteVisitorA class, which inherits from an abstract visitor class
class ConcreteVisitorA : public Visitor {
public:
ConcreteVisitorA();
~ConcreteVisitorA();
void VisitElement(Element e);
};
void ConcreteVisitorA::VisitElement(Element e)
{
int numNodes = e.GetNumNodes();
int numAttrs = e.GetNumAttrs();
cout << "Visitor has found " << numNodes << " noes\n";
e.nodeVec[0]->Accept(this);
}
The problem is when it gets to the last line of VisitElement, where the first member of the vector is visited i get the error
concreteVisitorA.cc:20: error: no matching function for call to 'Node::Accept(ConcreteVisitorA* const)'
node.h:9: note: candidates are: virtual void Node::Accept(Visitor&)
The Accept method has to have visitor passed to it by reference, because it is abstract. But "this" is a pointer and the whole thing craps out. Any suggestions?
Marked Solved 
