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

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 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