Re: CINT improvement news

Nick van Eijndhoven (Nick@fys.ruu.nl)
Tue, 1 Jul 1997 09:32:28 +0200 (MET DST)

Hi Masa,
I have been out for a day or 2 and am now reading my emails in reverse
order as they came in, so maybe you have already sent me another mail about
the subject. However, from the scenario below I myself would prefer
method 1) to be implemented since to me this seems to be in line with the
ANSI proposed standard. I am not at all a specialist in C++ and therefore
let myself always guide by some text books adhering the ANSI standard.
Therefore it is important for me that the ROOT/CINT functionality should
at least provide a fully ANSI C++ compatible environment, such that
a simple user like me should no difference in coding for e.g. g++ to
compile code, or coding fopr ROOT/CINT.

Cheers,
Nick.

P.S. I hope the CINT major improvements will also cure the problem I
recently mentioned to you.

*----------------------------------------------------------------------*
Dr. Nick van Eijndhoven Department of Subatomic Physics
email : nick@fys.ruu.nl Utrecht University / NIKHEF
tel. +31-30-2532331 (direct) P.O. Box 80.000
tel. +31-30-2531492 (secr.) NL-3508 TA Utrecht
fax. +31-30-2518689 The Netherlands
WWW : http://www.fys.ruu.nl/~nick Office : Ornstein lab. 172
----------------------------------------------------------------------
tel. +41-22-7679751 (direct) CERN PPE Division / ALICE exp.
tel. +41-22-7675857 (secr.) CH-1211 Geneva 23
fax. +41-22-7679480 Switzerland
CERN beep : 13+7294 Office : B 160 1-012
*----------------------------------------------------------------------*

*** Masaharu Goto wrote :
>
> Rooters,
>
> I made a major improvement on CINT C++ interpreter.
>
> Operator precedence:
> CINT used to have different operator precedence to ANSI standard. This
> part was one of the oldest code which was rather messy. This time, I
> completely re-write this part with a better implementation. Operator
> precedence should be compliant to the standard now.
> The new version will be copied to CERN soon.
>
>
> And next is a question to Rooters about another enhancement.
>
> Operator new:
> I'd like to make an improvement on 'operator new' handling. Before I
> make a change, I'd like to ask ROOT users about my idea. Now, you can
> only use default operator new provided by OS and ROOT/CINT. You could
> overload operator new, but it is not a simple job. I have following
> alternatives of future enhancement.
>
> 1) ANSI/ISO standard says there is not default operator new with arena
> argument. Gussing that this is the most popular way of using overloaded
> new, CINT provides embedded operator new with arena argument. With
> this enhancement, a user can write following macro without having his
> own operator new().
>
> class Txxx;
> char buf[10000];
> Txxx *p1 = new Txxx;
> Txxx *p2 = new((void*)buf) Txxx;
> Txxx *p3 = new((void*)buf) Txxx[10];
>
> 2) Allow user to overload operator new at his one risk. Overloading
> operator new in interpreter environment is simple. But doing so in
> compiled code is not. One has to go throught painful thinking. I
> do not explain in detail , but there is an inevitable reason.
>
> I prefer to implement 1). Give me your opinion.
>
> Masaharu Goto
>