Istvan Buki wrote:

here is a small piece of code that use the posix_time system that fails to compile. I'm wondering whether it is a bug in the library or my usage of the library that is wrong. <snip>

Library code normally needs to be compiled separately into a library file that is then statically or dynamically linked with the client code. Boost is unusual in that many of its libraries contain only inline and template functions that are compiled along with the client code. However, the date_time, filesystem, graph, python, regex, signals, test, and thread libraries have some code that must be separately compiled. See the file tools/build/index.html in the Boost distribution or on www.boost.org.