I'm trying to integrate two applications. The first is configured to use fastcall and the other is using cdecl... The thing is that I get linking errors which says that boost uses thiscall? eh. However, i can change the other application to use fastcall too, but when i try to link the integrated application it says as i mentioned earlier that boost uses thiscall.

Can i configure boost to use whatever I want?

I presume that you are building your application with a non-standard calling convention as the default? The Boost libraries are built with whatever your compilers default is, so if you want to build with fastcall say then something like: bjam -sTOOLS=vc-7_1 -sBUILD="<cxxflags>-Gr <threading>single/multi <runtime-link>static/dynmaic debug release" install Should work. John.