[fpc-pascal] constructor as procvar
dle3ab at angelbase.com
Sat Mar 20 18:26:25 CET 2010
How can I obtain a class type variable from an instance? I want to
create a second instance of the same descendant class (via the
constructor, which will take some parameters and make the new instance
Tobject.classtype returns TClass (class of TObject) which I first
assumed would work great. However I cannot seem to do a type conversion
from TClass to t_mammal_class (class of t_mammal)! So I am stuck here.
I tried just using TClass and skipping t_mammal_class, but then I can't
use my overriden constructor that takes special parameters.
Thanks in advance,
On Fri 19 Mar 2010, David Emerson wrote:
> Florian Klaempfl wrote:
> > Constructor procvars are indeed not supported but the way to achieve
> > what you want is to use class type variables
> > t_mammal_class = class of t_mammal;
> > function find_or_create_animal (color : byte;
> > pass_mammal_type : t_mammal_class) : t_mammal;
> > brown_pig := t_pig (pig_pen.find_or_create_animal (brown, t_pig));
> ah, that is exactly what I need. Works perfectly. Thanks much.
> fpc-pascal maillist - fpc-pascal at lists.freepascal.org
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