cpp Build and install the boost tools (bcp, quickbook, inspect, wave) Run "eselect boost update" even if version is already selected Build and install debug versions of the Boost libraries. These libraries are not used by default, and should not be used unless you're developing against Boost. Build and install only the debug version of the Boost libraries. Only enable this flag if you're developing against boost. Build multi-thread-compatible libraries instead of single-threaded only. Build libboost_locale. This library requires compatible C library interfaces, which might not be provided by uClibc or other embedded libraries. Install the full API documentation documentation. This takes over 200MB of extra disk space.