[boost] [Filesystem] Dual V2 + V3 support progress report

Subject: [boost] [Filesystem] Dual V2 + V3 support progress report
From: Beman Dawes (bdawes_at_[hidden])
Date: 2010-06-11 08:12:19

I've created a branch to develop dual V2 + V3 support via namespace
hoisting, as suggested by Scott McMurray, Andrey Semashev, and others.

See https://svn.boost.org/svn/boost/branches/filesystem3

Seems to work well, and is lots easier to use that the switching
approach currently in trunk. I've tested only on Windows, but will
give Linux and Mac OS X a try later today or tomorrow.

Namespace hoisting will break some existing V2 code:

* User specializations in namespace filesystem. This is presumably
very unusual, breaks noisily, and the fix is trivial, so I don't see
it as a show stopper.

* Possible ADL problems. I don't fully understand when this might be a
problem, but neither V2 or V3 hit it in any of the tests, so I doubt
it is very serious.

--Beman