friend specifier

friend specifier

Grants access to private class members

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  decl-specifier  := friend 

The friend specifier declares a friend function, class, or template. A friend declaration can appear only in a class or class template definition. A friend has full access to the private members of the class that contains the friend declaration. A friend function declaration can be a function definition.

If a class template contains a friend declaration, all instantiations of the template grant friendship. If the friend is a template declaration, all instantiations of the template are friends . If the friend is a template specialization or instantiation, only that specialization or instantiation is a friend.

Friendship is not transitive, nor is it inherited.

Example

 class list {  friend  bool operator==(const list& a, const list& b);  friend  class node;   ... }; 

See Also

class , declaration , template , Chapter 6, Chapter 7