C++重载operator的示例

来源：互联网发布：mac翻墙软件编辑：程序博客网时间：2024/05/22 11:30
以下示例中定义了一个class test, 重载了<, +, +=, =, ==, <<, >>等符号:
#include<iostream>#include<vector>using namespace std;class test{public:     int v;   /*构造函数*/     test():v(0){}     test(const int &a):v(a){}     test(const test &t1):v(t1.v){}        /*以下重载小于号 < */     //比较两个对象的大小      bool operator<(const test &t1) const{          return (v < t1.v);     }     //比较对象和int的大小      bool operator<(const int &t1) const{          return (v < t1);     }     //友元函数，比较int和对象的大小      friend inline bool operator<(const int &a, const test & t1){         return (a < t1.v);     }       /*以下重载赋值号 = */     //对象间赋值      test & operator=(const test &t1){         v = t1.v;         return *this;     }     //int赋值给对象      test & operator=(const int &t1){         v = t1;         return *this;     }       /*以下重载加号 + */     //对象加上 int      test operator+(const int & a){         test t1;         t1.v = v + a;         return t1;     }     //对象加对象      test operator+(test &t1){         test t2;         t2.v = v + t1.v;         return t2;     }       /*以下重载加等号 += */       //对象加上对象      test &operator+=(const test &t1){         v += t1.v;         return *this;     }       //对象加上int     test &operator+=(const int &a){         v += a;         return *this;     }   /*以下重载双等号 == */       //对象==对象      bool operator==(const test &t1)const{         return (v == t1.v);     }       //对象==int     bool operator==(const int &t1)const{         return (v == t1);     }         /*以下重载 输入>> 输出<< */     /*友元函数，输出对象*/     friend inline ostream & operator << (ostream & os, test &t1){         cout << "class t(" << t1.v << ")" << endl;         return os;     }     /*友元函数，输入对象*/     friend inline istream & operator >> (istream & is, test &t1){         cin >> t1.v;         return is;     }};int main(){     test t0, t1(3);     test t2(t1);     cout << t0 << t1 << t2;     cin >> t1;     t2 = t1;     t2 += t1;     t1 += 10;     cout << t2;     if(t1 < t2) cout << "t1 < t2";      else if(t1 == t2) cout << "t1 = t2";     else /* t1 > t2*/ cout << "t1 > t2";      cout <<endl;     system("pause");     return 0;}