[boost] Re: mpl::at_c as lambda

From: David Abrahams (dave_at_[hidden])
Date: 2004-07-17 20:19:22

"Scott Graham" <sgraham_at_[hidden]> writes:

> Hi
>
> Is it possible to make mpl::at_c lambda-able? 

I'm afraid not.  Lambda requires a uniform interface to metafunctions.
That's a big part of why the sample chapter 3 at
http://boost-consulting.com/mplbook/ goes on and on about the
importance of polymorphism.

Getting lambda to work with template arguments other than types would
require an exponential number of template specializations, and getting
it to work with *all* possible non-type template arguments, even just
for one-argument templates, would require an infinite number of
template specializations.

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com