http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50044
--- Comment #9 from Martin Lederhilger <m...@convergent-it.at> 2011-08-16 14:17:32 UTC --- Results for: template<class T> class INTERFACE A : public Base ... Case one without "extern template": warning is still there but links fine. Case two with "extern template": still undefined reference to `typeinfo for A<int>' I should note that I cannot use INTERFACE on the class template definition, because I want to explicitly instantiate the template in multiple DLLs and then I would need dllimport and dllexport at the same time on the class template definition. For example instantiate A<int> in A.dll, and A<float> in B.dll: When I want to use A<int> and A<float> in B.dll then I would need dllimport and dllexport at the same time. Thats why I want to apply INTERFACE to "extern template INTERFACE...". Output from nm for case two (with "extern template...") generated by i686-mingw32-nm dll.dll | i686-mingw32-c++filt > nm.txt
