iostreamoperatoroverloading.cpp

ThinkingC++中文版

//: C12:IostreamOperatorOverloading.cpp
// Example of non-member overloaded operators
//#include <iostream.h>
//#include "../require.h"
//#include <sstream>
//#include <string.h>
//using namespace std;

//#include <sstrea.h> // "String streams"
//#include <cstring.h>
#include "../require.h"
#include <string>
#include <iostream>
#include <sstream>

using namespace std ;


class IntArray {
  enum { sz = 5 };
  int i[sz];
public:
  IntArray() { memset(i, 0, sz* sizeof(*i)); }
  int& operator[](int x) 
  {
    require(x >= 0 && x < sz,
      "IntArray::operator[] out of range");
    return i[x];
  }
  friend ostream& fun(ostream& os , const IntArray& b);
  friend ostream& operator<<(ostream& os, const IntArray& ia);
  friend istream& operator>>(istream& is, IntArray& ia);
};


ostream& fun(ostream& os,const IntArray& b)
{
	os << b.i[0] << endl;
	return os;
}


ostream& operator<<(ostream& os, const IntArray& ia) {
  for(int j = 0; j < ia.sz; j++) {
    os << ia.i[j];
    if(j != ia.sz -1)
      os << ", ";
  }
  os << endl;
  return os;
}

istream& operator>>(istream& is, IntArray& ia){
  for(int j = 0; j < ia.sz; j++)
    is >> ia.i[j];
  return is;
}

void main() {
	 string str1("012");
    string str2("345");

  stringstream input("47 34 56 92 103");
  IntArray I;
  input >> I;
  I[4] = -1; // Use overloaded operator[]
  cout << I;
} ///:~