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digitalmars.D.learn - C# Indexers. how to implement them in D.. also property related.

reply BLS <windevguy hotmail.de> writes:
Hi, in C# you can do some thing like this.

public interface IDataErrorInfo
{
     // INDEXER	
     string this[string columnName] { get; }
   }
}

how to translate this into D2 ?
thanks in advance, bjoern
Jun 29 2010
next sibling parent reply "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Tue, 29 Jun 2010 09:21:34 -0400, BLS <windevguy hotmail.de> wrote:


 Hi, in C# you can do some thing like this.

 public interface IDataErrorInfo
 {
      // INDEXER	
      string this[string columnName] { get; }
    }
 }

 how to translate this into D2 ?
 thanks in advance, bjoern



string opIndex(string columnName);
Jun 29 2010
parent reply BLS <windevguy hotmail.de> writes:
On 29/06/2010 15:27, Steven Schveighoffer wrote:

 string opIndex(string columnName);



yeah this is what I did, too..
However defined as ;

interface I1 {
   string opIndex(string columnName);
}

is a no go. So can we say operator overloading within interfaces is not 
allowed in D2 ?

thanks again Steve.. try to learn the interface/property stuff.
Jun 29 2010
parent BLS <windevguy hotmail.de> writes:
On 29/06/2010 15:35, BLS wrote:

 On 29/06/2010 15:27, Steven Schveighoffer wrote:

 string opIndex(string columnName);



 yeah this is what I did, too..
 However defined as ;

 interface I1 {
 string opIndex(string columnName);
 }

 is a no go. So can we say operator overloading within interfaces is not
 allowed in D2 ?

 thanks again Steve.. try to learn the interface/property stuff.



Jeez, my mistake.. forget to create the implementation. sorry!
Jun 29 2010
prev sibling next sibling parent "Simen kjaeraas" <simen.kjaras gmail.com> writes:
BLS <windevguy hotmail.de> wrote:


 On 29/06/2010 15:27, Steven Schveighoffer wrote:

 string opIndex(string columnName);



 yeah this is what I did, too..
 However defined as ;

 interface I1 {
    string opIndex(string columnName);
 }

 is a no go.



Hm. That should have worked.


 So can we say operator overloading within interfaces is not allowed in  
 D2 ?



The new operator overloading scheme has problems with
interfaces. A damned shame if you ask me.

That said, opIndex does not use templates, and should thus
work no problem.


-- 
Simen
Jun 29 2010
prev sibling next sibling parent Trass3r <un known.com> writes:
 interface I1 {
    string opIndex(string columnName);
 }

 is a no go. So can we say operator overloading within interfaces is not  
 allowed in D2 ?



It should work.
Only opBinary etc doesn't work yet cause there are problems with template  
functions in interfaces.
Jun 29 2010
prev sibling parent "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Tue, 29 Jun 2010 09:55:50 -0400, BLS <windevguy hotmail.de> wrote:


 On 29/06/2010 15:35, BLS wrote:

 On 29/06/2010 15:27, Steven Schveighoffer wrote:

 string opIndex(string columnName);



 yeah this is what I did, too..
 However defined as ;

 interface I1 {
 string opIndex(string columnName);
 }

 is a no go. So can we say operator overloading within interfaces is not
 allowed in D2 ?

 thanks again Steve.. try to learn the interface/property stuff.



 Jeez, my mistake.. forget to create the implementation. sorry!



LOL!   :)

As others have said, templates do not yet work in interfaces, and there is  
another subtle problem: templates in interfaces are not virtual so they  
cannot enjoy covariance.  This is a problem for dcollections which uses  
operators in interfaces.

The only solution right now is to reimplement the template in the derived  
classes.

Not a fun situation...

-Steve
Jun 29 2010