Path: utzoo!attcan!uunet!lll-winken!ames!ucsd!rutgers!mit-eddie!bu-cs!mirror!necntc!necis!mrst!sdti!turner
From: turner@sdti.SDTI.COM (Prescott K. Turner)
Newsgroups: comp.lang.c++
Subject: Re:  inheriting constructors
Message-ID: <352@sdti.SDTI.COM>
Date: 26 Jan 89 18:04:33 GMT
References: <3477@tekcrl.CRL.TEK.COM>
Reply-To: turner@sdti.SDTI.COM (Prescott K. Turner, Jr.)
Organization: Software Development Technologies, Sudbury MA
Lines: 36

In article <3477@tekcrl.CRL.TEK.COM>, soiffer@tekcrl.CRL.TEK.COM (Neil Soiffer) says:
> [...] the program that I included that showed that in cfront, they
> [constructors] are occasionally inherited
What cfront does with your example seems very odd.  I've heard it said
so often that constructors are not inherited that I can't point out
when Dr. Stroustrup said it.  This non-inheritance is intentional.  What's
more, you are looking not just for constructors to be inherited, but
to be accessible by the name of the derived class.  Such a feature is not
described in the book or in any of the other papers describing the
definition of C++.

> In Stroustrup's book, the only comment on the first form "D d(5)" that
> I could find is on page 139, saying that the first form is an abbreviation
> of the second form.  Why should an abbreviation behave differently than
> the full form?
Indeed cfront treats them identically in the sample program you present.
It's g++ which handles them differently, and it's a bug.

> The *only* new behavior this class introduces is for the Press function.
> Why should "MyPushButton" have to (re)introduce the six constructors that
> are defined for "PushButton".
Yes, good example.

> Does this reference manual exist in some preliminary
> form and if so, does it discuss whether constructors are inherited in a
> correct implementation of c++?
Yes, where I work we are lucky to be among the reviewers of the revised
reference manual for C++.  It is not finished, so reviewing it has its
price as well as benefits.  I can't comment on what it says about
inheritance of constructors, but if it is silent we will mention that in
our review.
--
Prescott K. Turner, Jr.
Software Development Technologies, Inc.
375 Dutton Rd., Sudbury, MA 01776 USA        (508) 443-5779
UUCP: ...{harvard,mit-eddie}!sdti!turner    Internet: turner@sdti.sdti.com