static void Main()
{
ConcreteObjectA a = new ConcreteObjectA();
ConcreteObjectB b = new ConcreteObjectB();
StronglyTypedVisitor sv = new StronglyTypedVisitor();
//proper usage of code
a.AcceptVisitor(sv);
b.AcceptVisitor(sv);
//now lets try to do some tricks
GenericVisitor gv = new GenericVisitor();
try
{
//a.AcceptVisitor(gv); this will generate compile error
(a as IObject).AcceptVisitor(gv); //oooo Im so great!
}
catch (ArgumentException ae)
{
Console.WriteLine("—————————————————————————————n{0}", ae);
}
//example with synchronization lost!
try
{
//Im sure it was agreed that the GeneralVisitor accepts ConcreteB, maybe its just a bug, I will try with the interface
//b.AcceptVisitor(gv); //this will generate compile error
(b as IObject).AcceptVisitor(gv); //looks fine to me and the compilator, so it works!
}
catch (ArgumentException ae)
{
Console.WriteLine("—————————————————————————————n{0}", ae);
}
Console.ReadKey();
}
public void HandleVisit(ConcreteObjectB aObject)
{
Console.WriteLine("Visited by a strongly typed ObjectB instance");
}
public void HandleVisit(ConcreteObjectB aObjectB)
{
Console.WriteLine("Handle visit of class {0}", aObjectB);
}