[signals2] compilation error in fnoexception

[Akira Takahashi <faithandbrave@…>]

Boost.Signals2 compile error because Boost.Signals2 using try/catch grammar (not BOOST_TRY/BOOST_CATCH) in fnoexception environment. This ticket is feature requests (not bug).

// g++ main.cpp -fno-exceptions -I "C:\Library\Boost\1_49_0"
#define BOOST_NO_EXCEPTIONS
#include <boost/signals2.hpp>

int main ()
{
}

In file included from C:\Library\Boost\boost_1_49_0/boost/signals2/deconstruct.h
pp:29:0,
                 from C:\Library\Boost\boost_1_49_0/boost/signals2.hpp:15,
                 from main.cpp:2:
C:\Library\Boost\boost_1_49_0/boost/signals2/deconstruct_ptr.hpp: In function 'v
oid boost::signals2::detail::do_predestruct(const boost::signals2::predestructib
le_adl_barrier::predestructible*)':
C:\Library\Boost\boost_1_49_0/boost/signals2/deconstruct_ptr.hpp:48:15: error: e
xception handling disabled, use -fexceptions to enable