Re: [Boost-users] [mpl] Implementing includes_if

From: David Abrahams (dave_at_[hidden])
Date: 2007-03-20 08:55:53

on Sat Mar 17 2007, Tobias Schwinger <tschwinger-AT-isonews2.com> wrote:

> The problem comes down to that MPL can't know where one placeholder 
> expression starts and where another one ends (denoted by uppercase 
> identifiers, above):

There is an inherent limitation in that regard.  These kinds of
problems come up repeatedly, so Aleksey and I agree the library should
provide a solution.  We had a long discussion on the boost-devel list
where we talked about the same issues in terms of runtime lambda
expressions:

  http://lists.boost.org/Archives/boost/2005/01/78409.php

As I said, this thread is long (it contains a whole thread attached to
one message in the outer thread -- how appropriate!)  but it's worth a
read.

Incidentally, protect<> doesn't help as it does something different.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com