Declare a Function Template as a Friend of Another Class Template

Declare a Function Template as a Friend of Another Class Template

There are various forms of friend declarations within a class template: a non-template friend, a specialized template friend, and a class template friend. A function template can also be declared as a friend of a class template. For instance, you might add an overloaded operator == function template to test the equality of two Vector objects. By doing so, you ensure that for every specialization of Vector, the implementation will generate a corresponding specialization of the overloaded operator == as well. Unfortunately, the declaration of a function template friend is rather complex. This following example walks you through these intricate steps and demonstrates how to do the declaration.

In order to declare a template function as a friend, you first have to forward declare the class template and the friend function template as follows:

   template  class Vector; // class template forward declaration    // forward declaration of the function template to be used as a friend  template  bool operator== (const Vector& v1, const Vector& v2);

Next, you declare the friend function template inside the class body:

 template  class Vector  {  public:    //

See also  Monetize TikTok For Your Business

About Our Editorial Process

At DevX, we’re dedicated to tech entrepreneurship. Our team closely follows industry shifts, new products, AI breakthroughs, technology trends, and funding announcements. Articles undergo thorough editing to ensure accuracy and clarity, reflecting DevX’s style and supporting entrepreneurs in the tech sphere.

See our full editorial policy.

About Our Journalist