RE: [sv-ec] Explicitly typed constructors?

Jonathan,

Your proposal is very sensible. On fact, I had discussed some time ago
enhancing SV to allow the second form you propose (D1'new). The obvious
benefit of such an enhancement is that it does not require the
declaration of a temporary simply to construct the object. since this is
not a major show-stopper (only a convenience feature), I don't think we
should consider this enhancement for the upcoming standard.

	Arturo

-----Original Message-----
From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] On Behalf Of
Jonathan Bromley
Sent: Friday, August 03, 2007 8:51 AM
To: sv-ec@eda-stds.org
Subject: [sv-ec] Explicitly typed constructors?

hi sv-ec,

In some recent work I've frequently encountered the situation
that I have a variable of base class type, but wish to be
able to construct objects of various derived types and use 
the common base variable to reference them.  To construct the 
derived objects, I need a derived-type variable (don't I?):

  class Base; 
    .... 
    virtual function void v(); ...
    ....
  endclass : Base
  class D1 extends Base; .... endclass
  class D2 extends Base; .... endclass
  ....
  Base b;
  D1 d1;
  D2 d2;
  ....
  d1 = new;
  b = d1;
  b.v();
  ....
  d2 = new;
  b = d2;
  b.v();

It would be very nice if I could force new() to create 
an object of a derived-class type even though the result 
of new() is then assigned immediately to a base-class 
variable: something like

  b = D1::new();
  b.v();
  b = D2::new(); 
  b.v();

Or, maybe,

  b = D1'new();

Either way, the idea is to mirror Java's

  b = new D1();

Has this already been dismissed for some reason?
I'm no OOP guru, but I can't see any killer reason
why it should be unreasonable.

Thanks
-- 
Jonathan Bromley, Consultant

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