static data_t make(mesh_t const &m, target_shape_t shape, aux_t ml) {
data_t A(join(m.size_of_components(), shape), ml);
A() = 0;
return A;
}
static typename gf_t::data_t make(mesh_t const &m, target_shape_t, aux_t) {
auto s = m.size_of_components();
std::vector<Target> v(s[1]);
return std::vector<std::vector<Target>>(s[0], v);
}
