Based on the discussion around this question. I'd like to know how .so files/the ELF format/the gcc toolchain avoid problems passing classes defined purely in header files (like the std library). According to Jan in that answer, the dynamic linker/loader only picks one version of such a class to load if its defined in two .so files. So if two .so files have two definitions, perhaps with different compiler options/etc, the dynamic linker can pick one to use. Is this correct? How does this work with inlining? For example, MSVC inlines templates aggressively. This makes the solution I describe above untenable for dlls. Does Gcc never inline header-only templates like the std library as MSVC does? If so wouldn't that make the functionality of ELF described above ineffective in these cases?
How do .so files avoid problems associated with passing header-only templates like MS dll files have?
c++;c++11;gcc;dynamic linking