// OPT: -lncurses -Wno-conversion-null
// sample code to explain why C++11 now has nullptr

#include <string>
#include <sstream>
#include <iostream>
#include <curses.h>

using namespace std;

string makestr(int i) {
	stringstream ss;
	ss << i;
	return ss.str();
}

string makestr(long i) {
	stringstream ss;
	ss << i << 'L';
	return ss.str();
}

string makestr(char *s) {
	return string(s ? s : "");
}

template<typename T>
void display(T *data, int n) {
	if (data)
		for(int i=0;i<n;i++)
			cout << data[i] << endl;
}

template<typename D,typename P> // D is an object that can draw
		// P is a pointer to an object that D can draw
void draworigin(D drawer, P obj) {
	drawer.move_pen(0,0);
	drawer.draw(obj);
}

// uses the curses library
class asciiart {
public:
	asciiart() { initscr(); }
	~asciiart() { endwin(); }
	void move_pen(int x, int y) { 
		move(y,x);
	}
	void draw(const char *s) {
		if (s) printw(s);
		getch(); // to pause
	}
private:
	WINDOW *w;
};

int main(int argc, char **argv) {
	cout << "line 1: " << makestr(NULL) << endl;
	cout << "line 2: " << makestr(0) << endl;
	cout << "line 3: " << makestr(nullptr) << endl;

	if (nullptr) cout << "should not get here" << endl;
	else cout << "nullptr convertable to bool" << endl;

	int num[4] {1,3,2,4};
	display(num,4);
	//display(nullptr,0); // won't compile -- cannot determine type of T
	//display(NULL,0); // won't compile -- same problem
	
	char ch;
	cin >> noskipws >> ch;
	asciiart aa;
	draworigin(aa,"hello");
	draworigin(aa,nullptr);
	draworigin(aa,"bye");
	//draworigin(aa,NULL); // this line won't compile -- asciiart doesn't
		// have a draw method for int
}