为什么这段代码运行报错啊？
//Listing 10.10//operator++ returns a nameless temporary object#include <iostream>using namespace std;class Counter{public: Counter(); Counter(int val); ~Counter(){} int GetItsVal() const {return itsVal;} void SetItsVal(int x) {itsVal = x;} void Increment() {++itsVal;} Counter operator ++() {}private: int itsVal;};Counter::Counter():itsVal(0){}Counter::Counter(int val):itsVal(val){}Counter Counter::operator ++(){ ++itsVal; return Counter(itsVal);}int main(){ Counter i; cout<<"The value of i is "<<i.GetItsVal()<<endl; i.Increment(); cout<<"The value of i is "<<i.GetItsVal()<<endl; ++i; cout<<"The value of i is "<<i.GetItsVal()<<endl; Counter a = ++i; cout<<"The value of a: "<<a.GetItsVal(); cout<<" and i: "<<i.GetItsVal()<<endl; return 0;}