Re: typedef a template method?

[Angus Leeming]

Andre Poenitz wrote:

> On Thu, Mar 06, 2003 at 11:37:09AM +0000, Angus Leeming wrote:
>> Can I define a shortcut in FormCitation.C. Something like:
>> typedef getController<ControlCitation> controller;
> 
> I think so. What happens if you try?

I can't get the typedef to work. (See class ViewCitation in the 
attached file).

> [I would not use macros for that, even if it doesn't work...]

Hmm. I thought you'd say that ;-) Still it works, so I know a little 
more.

-- 
Angus
#include <ostream>
#include <string>

class ControllerBase;
class ViewBase;

class Dialog {
public:
	Dialog() : controller_(0), view_(0) {}
	void controller(ControllerBase * controller) { c_ = controller; }
	void view(ViewBase * view) { v_ = view; }
	ControllerBase & controller() { return *c_; }
	ViewBase & view() { return *view_; }
private:
	ControllerBase * c_;
	ViewBase * v_;
};


class ControllerBase {
public:
	ControllerBase(Dialog & parent) : parent_(parent) {}
	virtual ~ControllerBase() {}
private:
	Dialog & parent_;
};


class ViewBase {
public:
	ViewBase(Dialog & parent) : parent_(parent) {}
        virtual void printcontroller() {}

        template<typename Controller>
        Controller & getController() const 
                { return dynamic_cast<Controller &>(parent_.controller()); }

private:
	Dialog & parent_;
};


class ControlCitation : public ControllerBase {
public:
	ControlCitation(Dialog & parent) : ControllerBase(parent) {}
	std::string const whoami() const { return "ControlCitation"; }
};


#define citationcontroller() getController<ControlCitation>()

class ViewCitation : public ViewBase {
public:
	// doesn't like this
	// function template "ViewBase::getController" is not a type name
	// typedef getController<ControlCitation> controller;

	ViewCitation(Dialog & parent) : ViewBase(parent) {}
        virtual void printcontroller() {
                std::cout << "ViewCitation's controller is "
			  << getController<ControlCitation>().whoami()
			  << std::endl;
                std::cout << "using that macro "
			  << citationcontroller().whoami()
			  << std::endl;
        }
};


int main() {
	Dialog dialog;
	dialog.controller(new ControlCitation(dialog));
	dialog.view(new ViewCitation(dialog));

	dialog.view().printcontroller();
	return 0;
	
}