shape.h

#pragma once

#include <string>
#include <iostream>


enum class shape_type
{
	n_Rectangle,
	n_Square,
	n_Circle,
	n_Triangle
};

class shape
{
public:
	/*   copy constructor:   */
	/* shape(cosnt shape&);  */

	// undefined behavior UB
	// virtual destructor
	virtual ~shape() = default;

	// abstruct
	virtual float area() const = 0; // pure virtual method
	virtual float perimeter() const = 0;
	virtual float circumference() const = 0;
	virtual std::ostream& shape_info(std::ostream&) const = 0;
	virtual std::string shape_details() const = 0;
};



std::ostream& operator<<(std::ostream& os, const shape& sp);

/*
std::ostream& operator<<(std::ostream& os, const rectangle& rect);
std::ostream& operator<<(std::ostream& os, const square& sq);
std::ostream& operator<<(std::ostream& os, const circle& cir);
std::ostream& operator<<(std::ostream& os, const triangle& tri);
*/