C++ Tutorial/Operator Overloading/custom inserter

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A custom inserter (

#include <iostream> 
using namespace std; 
 
class MyClass { 
public: 
  int x, y, z;
  MyClass(int a, int b, int c) { x = a; y = b; z = c; } 
}; 
 
// Display X, Y, Z coordinates - MyClass inserter. 
ostream &operator<<(ostream &stream, MyClass obj) 
{ 
  stream << obj.x << ", "; 
  stream << obj.y << ", "; 
  stream << obj.z << "\n"; 
  return stream;  // return the stream 
} 
 
int main() 
{ 
  MyClass a(1, 2, 3), b(3, 4, 5), c(5, 6, 7); 
 
  cout << a << b << c; 
 
  return 0; 
}
1, 2, 3
3, 4, 5
5, 6, 7

Use a friend to overload

#include <iostream> 
using namespace std; 
 
class MyClass { 
  int x, y, z; // 3-D coordinates - now private 
public: 
  MyClass(int a, int b, int c) { x = a; y = b; z = c; } 
  friend ostream &operator<<(ostream &stream, MyClass obj); 
}; 
 
// Display X, Y, Z coordinates - MyClass inserter. 
ostream &operator<<(ostream &stream, MyClass obj) 
{ 
  stream << obj.x << ", "; 
  stream << obj.y << ", "; 
  stream << obj.z << "\n"; 
  return stream;  // return the stream 
} 
 
int main() 
{ 
  MyClass a(1, 2, 3), b(3, 4, 5), c(5, 6, 7); 
 
  cout << a << b << c; 
 
  return 0; 
}
1, 2, 3
3, 4, 5
5, 6, 7
Источник — «http://cppe.ru/index.php?title=C%2B%2B_Tutorial/Operator_Overloading/custom_inserter&oldid=2810»