Xref: utzoo comp.lang.c++:11549 comp.std.c++:583
Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!apple!sun-barr!cs.utexas.edu!uunet!pdn!tscs!tct!chip
From: chip@tct.uucp (Chip Salzenberg)
Newsgroups: comp.lang.c++,comp.std.c++
Subject: Re: Why no renew
Message-ID: <27B2E0B5.56BB@tct.uucp>
Date: 8 Feb 91 17:32:13 GMT
References: <2488@bnlux0.bnl.gov> <10895@pasteur.Berkeley.EDU>
Followup-To: comp.std.c++
Organization: Teltronics/TCT, Sarasota, FL
Lines: 28

According to jbuck@galileo.berkeley.edu (Joe Buck):
>You're free to propose a "renew" operator as an extension if
>you want, but remember that new is not equivalent to malloc,
>and delete is not equivalent to free; new calls a constructor
>and delete calls a destructor.

How about a renew that is defined only for arrays?  The "delete [] p"
statement requires that the size of the allocated arrray be remembered
by the implementation.  So renew has the information it needs to call
constructors and destructors appropriately.

I would like to see something like:

     class X { ... };
     X *p = new X[1];         // calls p[0].X::X()
     p = renew(p, 2);         // calls p[1].X::X()
     p = renew(p, 1);         // calls p[1].X::~X()
     delete [] p;             // calls p[0].X::~X()

Remember that the current definition of "::operator new()" loses all
type information, so we need some language support for this feature to
work.

How about it?
-- 
Chip Salzenberg at Teltronics/TCT     <chip@tct.uucp>, <uunet!pdn!tct!chip>
 "Most of my code is written by myself.  That is why so little gets done."
                 -- Herman "HLLs will never fly" Rubin