Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!boulder!ccncsu!ncr-fc!frodo
From: frodo@ncr-fc.FtCollins.NCR.COM (David Fletcher)
Newsgroups: comp.lang.c++
Subject: Constructors for (non-public) derived classes
Message-ID: <200@ncr-fc.FtCollins.NCR.COM>
Date: 4 Mar 89 17:08:51 GMT
Reply-To: frodo@ncr-fc.UUCP (David Fletcher)
Followup-To: comp.lang.c++
Distribution: na
Organization: NCR  Fort Collins, Colorado
Lines: 39

I have a problem with calling a constructor for a derived class that is
not publicly derived from a base class.  These classes look something
like:


class B				| class D : B   // *NOT* public B
{				| {
 public:			|  public:
  B(various args);		|   D(various args);
  B(B& Ref);			|   D(D& Ref);
  void operator=(B& Ref);	|   void operator=(D& Ref);
  ~B();				|   ~D();
 protected:			|  protected:
 private:			|  private:
}				| }

Here are the constructors for them:

   B::B(various args) {}
   B::B(B& Ref) {}
   // ...

   D::D(various args) : (other various args) {}
   D::D(D& Ref) : (Ref) {}			<== offending line


Now, using AT&T 1.2.1 I get an error from the compiler that looks like:

   "foo.cc", line 116: error: bad argument list for overloaded base::base()

However, if I publicly derive D (i.e., class D : public B {} ) then
everything is okey-dokey.  Why does it matter that the class is not
publicly derived?  I can't find anything in the C++ documentation/book
that says this is verbotten.  Thanks for the help.
-- 
David Fletcher, NCR Microelectronics
2001 Danfield Court,
Ft. Collins, CO 80525	  |	"... Let everything else go ..."
(303) 223-5100 x 241	  |			-- Phil Keaggy