Re: [Boost-users] Re: [regex] Unresolved external symbols under VC7.1w/dynamic linking

#define BOOST_DYN_LINK

OK, that's the problem: BOOST_DYN_LINK is an internal Boost macro that instructs the auto-linking code to link to a dll, but it doesn't tell the code to add __declspec(dllimport) where needed. You should be defining one of: BOOST_ALL_DYN_LINK: make all Boost libs link as dll's. BOOST_REGEX_DYN_LINK: make regex only link as a dll.

My project settings are: - Runtime Lib: Multithreaded-DLL (/MD)

Be careful not to mix /MD with /D_DEBUG, it confuses the auto-link code (not really a Boost issue, it affects any libray that's linked with #pragma comment). HTH, John.