Re: [Boost-users] [tuple] Function object for nth element of a tuple

Subject: Re: [Boost-users] [tuple] Function object for nth element of a tuple
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2009-07-05 16:22:35

On Sun, 5 Jul 2009, joel wrote:

> Jeremiah Willcock wrote:
>> Is there a standard way to get a function object that extracts a fixed 
>> element from a tuple?  There is a boost::tuples::detail::get_class<N> that 
>> does what I want, but it does not have result_type and does not appear to 
>> be officially supported.
> isn't boost::fusion::at_c a proper PFO that works on tuple ?

Do you mean <URL:http://spirit.sourceforge.net/dl_more/fusion_v2/libs/ 
fusion/doc/html/fusion/sequence/intrinsic/functions/at_c.html>?  That does 
not appear to be a function object, but a plain function.  Also, shouldn't 
something like this (and getting the nth element type from a tuple) be in 
the tuple library itself?

-- Jeremiah Willcock