Factory class

[Denis Koroskin]

On Thu, 19 Mar 2009 22:58:02 +0300, Simen Kjaeraas <simen.kjaras at gmail.com> wrote:

> On Thu, 19 Mar 2009 18:06:37 +0100, KeepYourMind  
> <vyacheslav at blue-code.org> wrote:
>
>> Sean Kelly Wrote:
>>
>>> KeepYourMind wrote:
>>> >
>>> > What i need to do for pizza.doSomeA() begin work?
>>>
>>> cast pizza to CoolPizza.
>>
>> Problem is i dont know what class returned. "char[] name" is dynamic  
>> and getting from command-line arguments.
>
> Then you need some test to see if it really is a CoolPizza.
>
> void main( string[] args ) {
>     auto pizza = PizzaFactory.factory( args[1] );
>     pizza.doSome( );
>     if ( args[1] == "CoolPizza" ) {
>         ( cast( CoolPizza ) pizza ).doSomeA( );
>     }
> }

Not like that. Here is a better way:

auto pizza = PizzaFactory.factory( name );
pizza.doSome();
if (auto cool = cast(CoolPizza)pizza) {
    cool.doSomeA();
}