Attempting to compile inkscape-0.47_pre0 produces: checking boost/concept_check.hpp usability... no checking boost/concept_check.hpp presence... no checking for boost/concept_check.hpp... no configure: error: You need the boost package (e.g. libboost-dev) creating a symlink: /usr/include/boost -> /usr/include/boost-1_37/boost/ allows the configure script to detect the files, but I'm sure this isn't the ideal solution
"eselect boost" is what you want. The new slotted boost (1.35-r5 and later) have this small trouble that the ebuild doesn't set the boost version to use, so apps fail to detect it. There's a bug open for it, but right now users have to manually fix that.