[boost] Re: once again: boost.bind namespace conflicts and how to solvethem

From: David Abrahams (dave_at_[hidden])
Date: 2004-11-29 17:26:08

Peter, I've been expecting for some time that you were going to put the 
placeholders in a sub-namespace of boost, if only to avoid the ODR 
violations it is currently causing.  No?

The fact that I have to write mpl::_1 just to avoid colliding with 
<unnamed>::_1 is disconcerting at best.  If another library came along 
and did what boost/bind/placeholders.hpp does, it would cause a clash.

My suggestion, assuming you care about backwards compatibility, is:

boost/bind/placeholders.hpp

   declares placeholders in namespace boost::bind::placeholders.

boost/bind/bind.hpp

   has the current contents of boost/bind.hpp, except that
   placeholders are not declared in the <unnamed>::

boost/bind.hpp

   #include <boost/bind/bind.hpp>
   #include <boost/bind/placeholders.hpp>
   namespace { using namespace boost::bind::placeholders; }

Is something wrong with that?
-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com