Xref: utzoo comp.lang.c++:13582 comp.std.c++:925
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!wuarchive!uunet!news.uu.net!microsoft!jimad
From: jimad@microsoft.UUCP (Jim ADCOCK)
Newsgroups: comp.lang.c++,comp.std.c++
Subject: Re: Constructor Limitation: [Was: Re: Constructor question]
Message-ID: <72461@microsoft.UUCP>
Date: 20 May 91 20:59:57 GMT
References: <1991Apr2.110623.22219@and.cs.liv.ac.uk> <20164@alice.att.com> <HAYDENS.91Apr17113619@natasha.juliet.ll.mit.edu> <1991Apr18.005426.21863@dragon.wpd.sgi.com> <71952@microsoft.UUCP> <DSOUZA.91May3150307@gwen.cad.mcc.com>
Reply-To: jimad@microsoft.UUCP (Jim ADCOCK)
Organization: Microsoft Corp., Redmond WA
Lines: 29

In article <DSOUZA.91May3150307@gwen.cad.mcc.com> dsouza@gwen.cad.mcc.com (Desmond Dsouza) writes:

>  You cannot compute any temporaries (e.g. common subexpressions) 
>  which are needed for initialization of such data members.

Consider:

----

int F1(int j) { /* something really really big and horrible here */ return j;}

class A {
  public: A(int m, int n);
};

class B {
public:
  B (int j);
private:
  int f1;
  A a1;	// initialized with F1(j), F1(j)+1 for some horribly complex F1
};

B::B(int j)
// how can I share the computation of F1(j) here ??? !!! Try the following:
: f1(F1(j)), a1(f1, f1+1)
{
  // this part does not help: I cannot modify a1 at this point.
}