Re: [boost] [lambda] Binding to templated functions

From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2008-07-22 07:28:42

Robert Jones wrote:
>   typedef pair<int, S *> Pair;
>   vector<Pair> pairs;
>   bool trueForAll = ( find_if( _1, _2, _3 ) == _2 )(
>       pairs.begin( ),
>       pairs.end( ),
>       ! bind( & S :: predOfS, bind( & Pair :: second, _1 ) ) );
> }
> 
> The last line gives me compile errors.
> 
> Two things:
> - I think I need to specicy the template parameters to find_if, but I'm not
> sure quite what they are!

Why are you even doing this?
find_if(pairs.begin(), pairs.end(), your_lambda_expression) is sufficient.

Otherwise, it is more practical to use a lazy function. Phoenix is
better for that, and it actually already provides lazy versions of
standard algorithms.

> - The error message reckons the last arg to find_if is placeholder<4>, not
> placeholder<3>, why?

Because _1 is placeholder<0>.