Visitor pattern, double despatching

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I'm using void*

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and c-style casts all over the place.

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I'd like to move this to template parameters and so every recieve function for each object in the game could have their own proper types.

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Someone said I need to use double despatching and the visitors pattern but left it at that and I have no idea where to start.

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Original post by the Speed Bump
C++ casts are ugly in the hopes that it will make you not want to use casts. (it''s a shame that C-style casts are still legal C++)

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Original post by PeterTarkus
What kind of dumb advice is that? Oh, you''re from Canada.

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class Entity
{
public:
// note the use of the elipse operator

virtual Recieve(...) = 0;
};

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class Entity
{
public:
// note the use of the elipse operator
virtual Recieve(...) = 0;
}; 

Then any derived class can put any types in there and any amount of arguements, and it will work correctly?

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struct Entity {
    virtual void recieve(EntityMessage* msg) {
        msg->visit(this);
    }

    virtual void recieveMoveMessage(MoveMessage* m) = 0;
    virtual void recieveStopMessage(StopMessage* m) = 0;
};

struct EntityMessage {
    virtual void visit(Entity* ent) = 0;
};

struct MoveMessage : EntityMessage {
    virtual void visit(Entity* ent) {
        ent->recieveMoveMessage(this);
    }
};

struct StopMessage : EntityMessage {
    virtual void visit(Entity* ent) {
        ent->recieveStopMessage(this);
    }
};