How can I overload the `

Overloading the << Operator Using Template Specialization

In C , it's possible to overload the friend operator << for template classes. However, it requires a different approach compared to regular friend function declarations.

To overload the << operator, a template specialization is necessary. This specialization involves creating a specific instance of the template class for which the operator is being overloaded. The specialized declaration is written as follows:

template <>
class Pair {
  // ...
  friend ostream& operator<<(ostream&, Pair&);
}
In this specialization, the template arguments are left empty, as the compiler can infer them from the parameter list within the operator declaration.
The original declaration of the << operator in the posted code was a friend declaration, but it incorrectly attempted to overload the operator for all instances of the template class. Instead, by using template specialization as outlined above, a specific instance of the template class is made a friend, allowing the overloaded << operator to be used only for that instance.
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