[boost] [placeholders]

Subject: [boost] [placeholders]
From: Andrzej Krzemienski (akrzemi1_at_[hidden])
Date: 2010-07-27 11:41:37

Hi,
I have a problem with Boost.Bind placeholders. Namely, once I include
the <boost/bind.hpp> it automatically brings placeholders _1, _2, ..
into scope and I cannot use placeholders from other libraries like
Spirit.Qi any more. I.e. I can but I need to qualify them like qi::_1,
qi::_2, which is annoying. I include <boost/bind.hpp> in a precompiled
header, so I have no option of not including it.
Boost.Bind could define them in namespace boost::bind_placeholders and
we could control their visibility with namespace using directive. This
is what Spirit does, and it is cute. I guess I would not be able to
convince anyone that Bind should do the same.
But would it be possible to define placeholders _1, _2, ... as
something more generic in Boost, unrelated to any particular library?
Then boost::bind, would treat it as its own placeholders, Spirit
semantic actions would treat them as its own placeholders, but they
would be exactly same placeholders.

Regards,
&rzej