Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!snorkelwacker!ai-lab!rpk
From: rpk@wheaties.ai.mit.edu (Robert Krajewski)
Newsgroups: comp.lang.c++
Subject: Re: calling a constructor
Message-ID: <9713@rice-chex.ai.mit.edu>
Date: 5 Aug 90 19:44:09 GMT
References: <1990Aug1.145814.16140@dg-rtp.dg.com> <PCG.90Aug3163603@odin.cs.aber.ac.uk>
Reply-To: rpk@rice-chex.ai.mit.edu (Robert Krajewski)
Organization: MIT Artificial Intelligence Laboratory
Lines: 25

I don't really fancy myself a C++ expert, but doesn't the standard
C++ library provide an alternate (overloaded) form of new:

void *operator new ( long size, void *memAddress );

that effectively invokes the constructor properly ?  (This is found in
the _C++ Primer_, page 164, but should the long there actually be a
size_t ?)

Suppose IntArray is a class with a constructor that takes an int for
an argument:

#include <new.h>

char buf [ sizeof(IntArray) ];

// Normal new use
IntArray *pa = new IntArray(10);

// Give new a place
IntArray *pbuf = new (buf) IntArray( 10 );

-- 
Robert P. Krajewski
Internet: rpk@ai.mit.edu ; Lotus: robert_krajewski.lotus@crd.dnet.lotus.com