According to version 2.1 of the FHS, include files for the c++ compiler should be located in /usr/include/g++ (cf section 4.2, page 17 of the April 12, 2000 pdf version of fhs-2.1). libstdc++ places these header files in /usr/include/g++-3
the FHS is broken in this regard (in our opinion). We will not be changing this.