I have a multi-threaded application where I pass delegates between threads.  While I thought this was a good design in the beginning, I find myself having to create a lot of helper objects...  Is there any way to avoid all the extra typing?  Any candidate additions to the language that'd help? :)

The following results in a run time error:
void example(){
  foreach(foo x; objectList)
    passDelegate({x.func(7);});
}

The following works but is annoying to keep typing:

class Helper{
  foo x;
  int param;
  this(foo _x, int _param){
    x     = _x;
    param = _param;
  }
  void opCall(){x.func(param);}
}
void example(){
  foreach(foo x; objectList)
    passDelegate(&(new Helper(x,7)).opCall);
}

Jason House wrote:
> I have a multi-threaded application where I pass delegates between threads.  While I thought this was a good design in the beginning, I find myself having to create a lot of helper objects...  Is there any way to avoid all the extra typing?  Any candidate additions to the language that'd help? :)
> 
> The following results in a run time error:
> void example(){
>   foreach(foo x; objectList)
>     passDelegate({x.func(7);});
> }
> 
> The following works but is annoying to keep typing:
> 
> class Helper{
>   foo x;
>   int param;
>   this(foo _x, int _param){
>     x     = _x;
>     param = _param;
>   }
>   void opCall(){x.func(param);}
    static void delegate() create(foo x, int param)
    {
      return &(new Helper(x,param)).opCall;
    }
> }
> void example(){
>   foreach(foo x; objectList)
>     passDelegate(Helper.create(x,7));
> }

Like that?

	-- Daniel

-- 
int getRandomNumber()
{
    return 4; // chosen by fair dice roll.
              // guaranteed to be random.
}

http://xkcd.com/

v2sw5+8Yhw5ln4+5pr6OFPma8u6+7Lw4Tm6+7l6+7D i28a2Xs3MSr2e4/6+7t4TNSMb6HTOp5en5g6RAHCP  http://hackerkey.com/

Daniel Keep wrote:
> 
> Jason House wrote:
>> I have a multi-threaded application where I pass delegates between
>> threads.  While I thought this was a good design in the beginning, I
>> find myself having to create a lot of helper objects...  Is there any
>> way to avoid all the extra typing?  Any candidate additions to the
>> language that'd help? :)
>>
>> The following results in a run time error:
>> void example(){
>>   foreach(foo x; objectList)
>>     passDelegate({x.func(7);});
>> }
>>
>> The following works but is annoying to keep typing:
>>
>> class Helper{
>>   foo x;
>>   int param;
>>   this(foo _x, int _param){
>>     x     = _x;
>>     param = _param;
>>   }
>>   void opCall(){x.func(param);}
>     static void delegate() create(foo x, int param)
>     {
>       return &(new Helper(x,param)).opCall;
>     }
>> }
>> void example(){
>>   foreach(foo x; objectList)
>>     passDelegate(Helper.create(x,7));
>> }
> 
> Like that?
> 
> 	-- Daniel
> 

... or very similar.  I think I mean to do
passDelegate( &(new Helper(x,7)).opCall );

I found std.bind which provides the functionality I was looking for. The .ptr() threw me for a loop, but I have it down now.

passDelegate( bind(&x.func,7).ptr() );