C++代码重用——包含

#ifndef PAIRS_H
#define PAIRS_H

#include <iostream>
#include <valarray>


template <class T1,class T2>
class Pair
{
    private:
       T1 a;
       T2 b;
    public:
       T1 & first();
       T2 & second();
       T1 first() const {return a;}
       T2 second() const {return b;}
       Pair(const T1 & aval,const T2 & bval) : a(aval),b(bval) {}
       Pair() {}
       void Set_Pair(const T1 & aval,const T2 & bval);
       void Show(int ys);
       int  Sum(void);
};

template <class T1,class T2>
T1 & Pair<T1,T2>::first()
{
    return a;
}

template <class T1,class T2>
T2 & Pair<T1,T2>::second()
{
    return b;
}

template <class T1,class T2>
void Pair<T1,T2>::Set_Pair(const T1 & aval,const T2 & bval)
{
  a=aval;
  b=bval;

}

template <class T1,class T2>
void Pair<T1,T2>::Show(int ys)
{
  int i=0;
  for (;i<ys;i++)
  {
    cout <<"	 "<<a[i]<<"	"<<b[i] <<endl;
  }

}

template <class T1,class T2>
int Pair<T1,T2>::Sum(void)
{
  return b.sum();
}
#endif

#ifndef WINE_H
#define WINE_H

#include <string>
#include "pairs.h"
#include <valarray> 
using namespace std;


class wine
{
    typedef  valarray<int> ArrayInt;
    typedef  Pair<ArrayInt,ArrayInt> PairArray;
    private:
       string  name;
       PairArray year_bottles;
       int years;
    public:
        wine(){}
        wine(const char *l,int y,const int yr[],const int bot[]);
        wine(const char *l,int y);
        void GetBottles(void);
        void Show(void);
        int sum(void);
        string Label(void){return name;}
};
#endif

#include"wine.h"
#include"pairs.h"
#include<iostream>
//#include <stdlib>
#include<string>

using namespace std;

wine::wine(const char *l,int y,const int yr[],const int bot[])
 {
     name=*l;
     years=y;
     year_bottles.Set_Pair(ArrayInt(yr,y),ArrayInt(bot,y));
 }
wine::wine(const char *l,int y)
{
    name=*l;
    years=y;
}    
void wine::GetBottles(void)
{
    int i=0;
    ArrayInt year(years),bottle(years);
    cout << "Enter "<< name <<"data for "<<years <<" year(s):" <<endl;
    for(;i<years;i++)
    {
        cout << "Enter year: ";
        cin >>year[i];
        //cout << endl;
        cout << "Enter bottles for that year: ";
        cin >>bottle[i];
        //cout << endl;
    }        
    year_bottles.Set_Pair(year,bottle);
}
void wine::Show(void)
{
    
    cout << "wine: "<< name <<endl;
    cout <<"	 Year	 Bottles" <<endl;
    year_bottles.Show(years);        
    
    
}

int wine::sum(void)
{
    int s=0;
    s=year_bottles.Sum();    
    return s;
}

#include "wine.h"
#include <iostream>

using namespace std;

int main(void)
{
    cout << "Enter name of wine: ";
    char lab[50];
    cin.getline(lab,50);
    cin.sync();
    cout << "Enter number of years: ";
    int yrs;
    cin >> yrs;
    
    wine holding(lab,yrs);
    holding.GetBottles();
    holding.Show();
    
    const int YRS=3;
    int y[YRS]={1993,1995,1998};
    int b[YRS]={48,60,72};
    
    wine more("Gushing Grape Red",YRS,y,b);
    more.Show();
    cout << "Total bottles for " <<more.Label()
         << ": " <<more.sum() <<endl;
    cout <<"Bey
";
    return 0;
}

wine类包含string和Pair两个类，前者用于存储酒名，后者有2个valarray<int>对象，分别用于存储酿造年份和该年的瓶数。