//Trapzint.h  文件一，類聲明
#include <iostream>
#include <cmath>
using namespace std;
class F	//抽象類F的聲明
{
public:
	virtual double operator ()(double x) const=0;	//純虛函數重載運算符()
};
class Fun:public F	//公有派生類Fun聲明
{
public:
	double operator()(double x) const	//虛函數的內聯實現
	{
	      return log(1.0+x)/(1.0+x*x);	//被積函數
	}
};
class Integ	//抽象類Integ聲明
{
public:
	virtual double operator ()(double a,double b,double eps) const=0;
};
class Trapz:public Integ	//公有派生類Trapz聲明
{
public:
	Trapz(const F&pf):f(pf){}	//構造函數
	double operator ()(double a, double b,double eps) const;
private:
	const F &f;	//私有成員，F類對象的指針
};	
//End of file Trapzint.h