[fpc-pascal] How to set a type as a variable?

[leledumbo]

It can be implemented with RTTI or variants perhaps.


Anthony Walter-3 wrote:
> 
> Like so:
> 
> procedure Test;
> var
>   SomeType: TClass;
>   SomeObject: TObject;
> begin
>   SomeType := TStringList;
>   SomeObject := SomeType.Create;
>   (SomeObject as TStrings).Add('Hello World');
>   ShowMessage((SomeObject as TStrings)[0]);
>   SomeObject.Free;
> end;
> 
> On Mon, Aug 23, 2010 at 7:05 PM, Frank Church <vfclists at gmail.com> wrote:
> 
>>
>> I did this kind of thing some time ago, but have forgotten the details.
>>
>> Let us say you have something like TBaseType(Variable).Method, you want
>> to
>> let TBaseType be a variable so you can have some code like this.
>>
>> procedure (value:someType)
>> var
>>   variableType: TClass; //not quite sure here
>>   variableType := TypeOf(value);
>>
>> then further on you execute something like
>>
>> variableType(Variable).Method, rather than TBaseType(Variable).Method
>> because you can't hard code TBaseType because can't tell what it will be
>> at
>> runtime. I remember doing something like that with Delphi of old,
>> probably
>> Delphi 3 or Delphi 7
>>
>> Can someone help me with this, with some use cases as well?
>>
>> Thanks
>>
>> --
>> Frank Church
>>
>> =======================
>> http://devblog.brahmancreations.com
>>
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>>
> 
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> 

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