Re: [Boost-users] [Range & c++0x Lambdas] Can this be done?

Subject: Re: [Boost-users] [Range & c++0x Lambdas] Can this be done?
From: Nathan Ridge (zeratul976_at_[hidden])
Date: 2012-11-21 14:27:15

> On Wed, Nov 21, 2012 at 5:15 PM, Nathan Crookston  
> <nathan.crookston_at_[hidden]<mailto:nathan.crookston_at_[hidden]>> wrote: 
> Rob, 
>  
> On Wed, Nov 21, 2012 at 6:39 AM, Robert Jones  
> <robertgbjones_at_[hidden]<mailto:robertgbjones_at_[hidden]>> wrote: 
> Can the last line, labelled NOT Ok, be made to work? I think the lambda does 
> not publish its result as a bind does, so I suspect it's hopeless. Any  
> thoughts? 
>      // NOT Ok 
>      boost::range::push_back( out, in | transformed( []( S & s ) {  
> return s.i; } ) ); 
> } 
>  
> It seems trivial to have a nested result_type in all cases with a  
> lambda.  However, in C++11 there's no need for it due to decltype. 
>  
> Sadly, some compilers fall into a gap where result_of (boost or std)  
> doesn't use decltype and lambdas don't publish tr1-style result_type --  
> leaving code like the above in the lurch. 
>  
> Michel Morin wrote some code for adapting such a case which may be of  
> interest to you: http://lists.boost.org/boost-users/2012/01/72879.php 
>  
>  
> Right, thank you for that informative explanation. So, several  
> solutions, non perfect. Choose 
> your poison! 
>  
> - Rob. 

I've been turning on BOOST_RESULT_OF_USE_DECLTYPE for such occasions
and haven't had any problems with it.

Regards,
Nate