Is friendship inherited in C++?

Question

Suppose I have a Base class:

class Base {
    friend SomeOtherClass;
};

And there is another (different) class that inherits from Base:

class AnotherClass : public Base {}

Is friendship inherited as well?

Yet another question that should have been answered easily using a COMPILER. — shoosh, Feb 28 '09 at 11:39
@shoosh: compilers do not necessarily conform to standards. Such a question should be answered by the standard, not compilers. — Hosam Aly, Mar 01 '09 at 07:58
@shoosh Which compiler? VS for windows or g++ for unix? Which version of C++ standard? There's many questions you can ask even if you compiler works or doesn't work. — FreelanceConsultant, Aug 23 '15 at 17:56
Perhaps a good question to ask now is can you make it such that friendship is inherited? It would certainly be useful for what I am doing rather than writing out a list of all the classes I want to have "friendship". — FreelanceConsultant, Aug 23 '15 at 17:57

score 19 · Accepted Answer · answered Feb 28 '09 at 10:57

19

In principle, a derived class inherits every member of a base class except:

* its constructor and its destructor
* its operator=() members
* its friends

So, no. Friends are not inherited.

answered Feb 28 '09 at 10:57

simplyharsh

6

It's interesting that you chose the exact wording to say that as this website: http://www.cplusplus.com/doc/tutorial/inheritance/ – dicroce Apr 24 '09 at 20:48
Perhaps a good question to ask now is can you make it such that friendship is inherited? It would certainly be useful for what I am doing rather than writing out a list of all the classes I want to have "friendship". – FreelanceConsultant Aug 23 '15 at 17:57

score 9 · Answer 2 · 2009-02-28T11:14:49.697

9

No it isn't.

Edit: To quote from the C++ Standard, section 11.4/8

Friendship is neither inherited nor transitive.

edited Feb 28 '09 at 11:14

answered Feb 28 '09 at 10:59

score 7 · Answer 3 · answered Feb 28 '09 at 10:57

7

answered Feb 28 '09 at 10:57

Daniel Bruce

The example in the link shows the opposite case to the OP's question. I'd like to add that `SomeOtherClass` will have access to the `Base` fields and methods inherited in objects of `AnotherClass`. – Hosam Aly Feb 28 '09 at 11:06

3 Answers3