[Boost-users] Is there a way for a library to add symbols to the standard headers ?

Hello To write a library to add a POSIX emulation layer on Windows, is there a way to add symbols from my library to C/C++ standard library headers, without getting into recursive inclusion ? For example, is there a way to get the 'Additions to fstream' from the boost::filesystem library, actually look like they are added to the standard <fstream> header ? I know users can use #include "cstdio" (with quotes instead of brackets) throughout a project, in order to later be able to include some local version of the header, if the need for it arise during during some porting at a later time for example. However this works for user-level code, while for a library it is not that simple any more ... Thank you, Timothy Madden