class operator++();用于重载先加一(减一)然后运算的情况
class operator++(int);用于重载先运算,然后加一(减一)的情况
系统会根据是++class 还是 class ++来进行判断使用那一个重载函数,重载函数中的内容需要用户自己进行定义
例子一:
#include<iostream> using namespace std; class Counter { public: Counter() { v = 0; } Counter operator ++(); Counter operator ++(int); int v; }; Counter Counter::operator ++() { v++; return *this; } Counter Counter::operator ++(int) { Counter t; t.v = v++; return t; } int main() { Counter c; cout<<"c.v++:"<<c.v++<<endl; cout<<"++c.v:"<<++c.v<<endl; }
例子二:
#include<iostream> using namespace std; class counter { public: counter() { v = 0; } counter operator ++(); counter operator ++(int); void print() { cout<<v<<endl; } private: unsigned v; }; counter counter::operator ++() { v++; return *this; } counter counter::operator ++(int) { counter temp(*this); v++; return temp; } int main() { counter c; for(int i=0;i<8;i++) { c++; } c.print(); for(int i=0;i<8;i++) { ++c; } c.print(); return 0; }