友元friend在运算符重载中应用

友元friend在运算符重载中应用

 

#include  < conio.h >
#include  < string >
#include  < iostream >

using   namespace  std;

class  CProduct
{
public:
    CProduct(int high,int weight, string productName);
private:
    friend ostream& operator<<(ostream& os,CProduct &product);
private:
    int m_high;        //高
    int m_weight;      //重量
    string m_productName; //产品名称
} ;

 ostream &   operator << (ostream &  os,CProduct  & product)
  {
     os<<"Product Name:"<<product.m_productName<<" weight:"<<product.m_weight<<" high:"<<product.m_high<<endl;

     return os;
 }

 inline CProduct::CProduct( int  high, int  weight,  string  productName)
  {
     this->m_high = high;
     this->m_weight = weight;
     this->m_productName = productName;
 }

int  main( int  argc, char   * argv[])
{
    CProduct product(175,30,"pig");;
    cout<<product;

    getch();
    return 0;
}