Re: [Boost-users] Bind + Function + Arguments

From: Stjepan Rajko (stipe_at_[hidden])
Date: 2008-02-29 19:05:29

On Fri, Feb 29, 2008 at 6:08 AM, QbProg <tholag_at_[hidden]> wrote:
>
> [snip]
>
> function <void (int , int ) > FunctionOne;
> function < bool (int ) > FunctionTwo;
>
> class Implementor
> {
> public:
>      void ImplOne ( int , int );
>      bool ImplTwo ( int );
>  };
>
> void test ()
> {
>     Implementor i;
>
>     FunctionOne = bind ( &Implementor::ImplOne , &i , _1 , _ 2);
>     FunctionTwo = bind (&Implemenetor::ImplTwo, &i , _1);
>
>    /* I Would be nice to do something like this, with parameter "guessing"
> */
>      // FunctionOne = GenericBind ( &Implementor::ImplOne ,&i);
>     // FunctionTwo = GenericBind ( &Implementor::ImplTwo, &i);
>
>   /* This will greatly remove verbosity! */
>   /* Actually I do */
>   #define Bind0(A,B) bind(A,B)
>  #define Bind1(A,B) bind(A,B,_1)
>  #define Bind2(A,B) bind(A,B,_1,_2)
>  ......
>  FunctionOne = Bind2 ( &Implementor::ImplOne , &i );
>  FunctionTwo = Bind1 ( &Implementor::ImplTwo , &i);
>   }
>
> It would be usefoul to make library callbacks more usable, insteat of
> writing a long list of arguments each time.
> It is possible with current implementation?
>

I have something in the dataflow library that I am planning to take in
the direction you're suggesting.  The current syntax allows something
like this:

FunctionOne = make_slot_selector<void (int, int)> ( &Implementor::ImplOne , i );
FunctionTwo = make_slot_selector<bool (int)>( &Implementor::ImplTwo , &i);

So it's not (yet) quite what you're looking for, but when the member
function is not overloaded I don't think I need the signature to be
specified explicitly, and can provide something like

FunctionOne = make_slot_selector( &Implementor::ImplOne , i );

But I haven't had time to try it yet :-)  I was going to try to do one
last push this weekend to get this lib submitted for review, maybe as
a part of that effort I can give this a whirl.

Stjepan