实现一个功能类似Any的类

#include<iostream>#include<algorithm>#include<string>#include<stdexcept>using namespace std;enum Type{Int,Dou,Str};class Any{private: void *ptr; Type type;public:Any();~Any();Any operator=(int x);Any operator=(double x);Any operator=(string x);operator int();operator double();operator string();};Any::Any(){ ptr=0;}Any::~Any(){// ptr;}Any Any::operator =(int x){ if(ptr!=0) { switch(type) { case Int: delete (int*)ptr; break; case Dou: delete (double*)ptr; break; case Str: delete (string*)ptr; break; } } ptr=new int(x); type=Int;}Any Any::operator =(double x){ if(ptr!=0) { switch(type) { case Int: delete (int*)ptr; break; case Dou: delete (double*)ptr; break; case Str: delete (string*)ptr; break; } } ptr=new double(x); type=Dou;}Any Any::operator =(string x){ if(ptr!=0) { switch(type) { case Int: delete (int*)ptr; break; case Dou: delete (double*)ptr; break; case Str: delete (string*)ptr; break; } } ptr=new string(x); type=Str;} Any::operator int(){ if(type!=Int) throw logic_error("it's not a integer!"); else return *((int*)ptr);}Any::operator double(){ if(type!=Dou) throw logic_error("it's not a integer!"); else return *((double*)ptr);}Any::operator string(){ if(type!=Str) throw logic_error("it's not a integer!"); else return *((string*)ptr);}int main(){ Any one; one=4.55; cout<<(double)one<<endl; one=400; cout<<(int)one<<endl; one=string("world"); cout<<(string)one<<endl; try { cout<<(int)one<<endl; } catch(logic_error err) { cout<<err.what()<<endl; } Any *ptr=&one; delete ptr;return 0;}