hello, i have this definition that works: array_2D_double psf_cartesian_centered(boost::extents[range_ext(indiceBegin,indiceEnd+1)][range_ext(indiceBegin,indiceEnd+1)]); but i want to use this writing to improve reading of my code in a more natural way: array_2D_double psf_cartesian_centered2[ boost::indices[indiceBegin <= array_2D_double::index_range() < indiceEnd][indiceBegin <= array_2D_double::index_range() < indiceEnd] ]; unfornunately this does not work , i read one hundred times the boost tutorial and documention qhere it is written something like this should ... what is my error? regards, damien