Here's the only non-trivial warning that pops up during the gcc3 build of Celestia using April 2002 dev tools on OS X. I'm no STL expert myself, so I don't really know what the best course of action would be to avoid needing implicit typenaming. It also shows up once in starbrowser.cpp for a multiset iterator (StarSet::iterator).
../src/celutil/resmanager.h: In member function `ResourceHandle ResourceManager<T>::getHandle(const T&)':
../src/celutil/resmanager.h:62: warning: `typename std::map<T, ResourceHandle, std::less<_Key>, std::allocator<std::pair<const T, ResourceHandle> > >::iterator' is implicitly a typename
../src/celutil/resmanager.h:62: warning: implicit typename is deprecated, please see the documentation for details