message: "This shall not happen": that's what assert is for.
diff: @@ -169,10 +169,9 @@ int main(int argc, char **argv) {
  std::cout << "filtration = " << filtr << std::endl;
  #endif // DEBUG_TRACES
  simplex_tree.insert_simplex(the_simplex, filtr);
  - if (the_alpha_value_iterator != the_alpha_values.end())
  + GUDHI_CHECK(the_alpha_value_iterator != the_alpha_values.end(),
  + "CGAL provided more simplices than values");
  ++the_alpha_value_iterator;
  - else
  - std::cout << "This shall not happen" << std::endl;
  }
  #ifdef DEBUG_TRACES
  