[Boost-users] Preferred syntax on GCC 4.0

I can't find this in the documentation or on the web, surprisingly, so I thought I'd ask here: Should I be able to use "preferred syntax" with boost::signal using GCC 4.0? I get "ISO C++ forbids delcaration of 'signal' with no type" errors, and portable syntax works fine. If it's relevant, I'm using the Apple build of GCC on OS X 10.4.8. Best, Austin