一道不知如何下手的C++问题

Question

int main(){
printf("1:");
int i = CRO();
printf("2:");
float f = CRO();
printf("3:");
void p = CRO();
printf("4:");
CRO();
}
程序输出为：
1：int
2：float
3: void
4：void

请设计一个CRO()满足以上输出。

Answer 1

呵呵，这样行不行！

#include "stdafx.h"
#include <iostream>

using namespace std;

struct CRO 
{
  #define void void *

  CRO() { type_ = "void"; }
  ~CRO() { cout << type_.c_str() << endl; }
  operator int() { type_ = "int"; return 0; }
  operator float() { type_ = "float"; return 0.0; }
  operator void () { type_ = "void"; return 0; }
private:
  string type_;
};

int main()
{
  printf("1:");
  int i = CRO();
  printf("2:");
  float f = CRO();
  printf("3:");
  void p = CRO();
  printf("4:");
  CRO();
  system("PAUSE");
  return 0;
}