[boost] [Config] proposal of new macro, BOOST_DECL :follow up for boost::noncopyable & vc7.1 & dll

From: Francis ANDRE (francis.andre_at_[hidden])
Date: 2004-11-03 07:32:52

Hi Developers

When using the boost.thread package as a dll under vc7.1, one gets for each
reference of boost::mutex  the C4275 warning for the inherited noncopyable
class (in fact 5 times, one for mutex, one for timed_mutex, one for
try_mutex, one for thread, and one for thread_group!!)

c:\boost\include\boost-1_32\boost\thread\mutex.hpp(34) : warning C4275:
non - DLL-interface 'boost::noncopyable_::noncopyable' used as base for
DLL-interface 'boost::mutex'

In order to avoid such warning, it would be nice to redefine -- 
again(sic) -- the BOOST_DECL macro and put it as a decorator for all
dependent classes used by the boost libraries that could be generated as a
dll.(thread, regex, filesystem, and so on).

With the empty string as default value in boost/config.hpp, it would the
responsability of each boost libraries to setup BOOST_DECL to the correct
value when using it as a dll.

Cheers

Francis ANDRE