Is there a way to detect (for instance with compiler warning) if classes are declared friend but do not access private members, ie. when friendship is useless?
views:
170answers:
4
+3
A:
Compiler warnings are not standardised, so this depends on your specific compiler(s). I would be very surprised if any of them supported this, however. A similar situation would be if you had a public member function which was only called by other public members (meaning it needn't be public), and once again I don't think any compilers detect this.
Doing either of these tests would mean extra work for the compiler writers, and I doubt if they would see them as sufficiently useful to implement.
anon
2010-07-13 13:29:15
I didn't quite understand your example of public members, but otherwise I agree with your answer.
Helltone
2010-07-13 13:55:05
@Helltone: I guess he means that if a public member function is accessed only through other functions of the same class, it need not be public at all.
casablanca
2010-07-13 15:38:11
+2
A:
Not that I know of. Maybe there's a refactoring tool out there that can do it. You can always try removing the friendship and see if it still compiles, but that might be time consuming for a large project.
Etienne de Martel
2010-07-13 13:29:35
+6
A:
I don't know how to detect this using compiler warnings but another way of doing this would be to go to your class definition file and do a search & replace for friend class with /*friend*/ class and see if it still compiles. Of course, this could get rather tedious for a large project.
Praetorian
2010-07-13 13:32:57
That causes a rather complex change in semantics. It would be rather hard to explain in a comment here, but basically name lookup differs.
MSalters
2010-07-13 14:22:13
@MSalters: Do you have a link where I can go read about it at? I'm curious to know what the change in semantics is.
Praetorian
2010-07-13 17:07:08
A:
You could compile the code to see that it compiles, then remove all 'friend' declarations (perhaps programmatically with sed) and sees if it still compiles.
orangeoctopus
2010-07-13 15:35:42
The following macro is an easy way to turn 'friend' (and the rest of that line of code) into a comment. This won't work if the friend declaration is multi-line. #define friend //
Aaron McDaid
2010-07-13 23:41:14