      static double mp_list_set_Joff_s(_cimg_math_parser& mp) {
        if (!mp.imglist.width()) return cimg::type<double>::nan();
        const unsigned int ind = (unsigned int)cimg::mod((int)_mp_arg(2),mp.imglist.width());
        CImg<T> &img = mp.imglist[ind];
        const int
          ox = (int)mp.mem[_cimg_mp_slot_x], oy = (int)mp.mem[_cimg_mp_slot_y],
          oz = (int)mp.mem[_cimg_mp_slot_z], oc = (int)mp.mem[_cimg_mp_slot_c];
        const longT
          off = img.offset(ox,oy,oz,oc) + (longT)_mp_arg(3),
          whd = (longT)img.width()*img.height()*img.depth();
        const T val = (T)_mp_arg(1);
        if (off>=0 && off<whd) {
          T *ptrd = &img[off];
          cimg_forC(img,c) { *ptrd = val; ptrd+=whd; }
        }
        return _mp_arg(1);
      }
      static double mp_list_set_Joff_s(_cimg_math_parser& mp) {
        if (!mp.imglist.width()) return cimg::type<double>::nan();
        const unsigned int ind = (unsigned int)cimg::mod((int)_mp_arg(2),mp.imglist.width());
        CImg<T> &img = mp.imglist[ind];
        const int
          ox = (int)mp.mem[_cimg_mp_slot_x], oy = (int)mp.mem[_cimg_mp_slot_y],
          oz = (int)mp.mem[_cimg_mp_slot_z], oc = (int)mp.mem[_cimg_mp_slot_c];
        const longT
          off = img.offset(ox,oy,oz,oc) + (longT)_mp_arg(3),
          whd = (longT)img.width()*img.height()*img.depth();
        const T val = (T)_mp_arg(1);
        if (off>=0 && off<whd) {
          T *ptrd = &img[off];
          cimg_forC(img,c) { *ptrd = val; ptrd+=whd; }
        }
        return _mp_arg(1);
      }