/++
  output hub<BR>
  check & generate output types requested
+/
template outputHub() {
  void outputHub(C,D)(C contents, D doc_matters) {
    auto rgx = Rgx();
    if (doc_matters.opt_action_bool["source"]) {
      /+ mixin SiSUoutputSource; +/
      writeln("source");
    }
    if (doc_matters.opt_action_bool["sisupod"]) {
      mixin SiSUpod;
      auto sisupod=SDPsisupod();
      sisupod.sisupod_assemble(doc_matters.source_filename);
      writeln("sisupod source");
    }
    if (doc_matters.opt_action_bool["text"]) {
      /+ mixin SiSUoutputText; +/
      writeln("text processing");
      // auto text=SDPoutput_text();
      // text.scroll(contents, bookindex_unordered_hashes, biblio, dochead_make, dochead_meta, fn_src, opt_action_bool);
    }
    if (doc_matters.opt_action_bool["html"]) {
      mixin SiSUoutputHTML;
      auto html=SDPoutputHTML();
      html.css_write;
      html.scroll(
        contents,
        doc_matters,
      );
      html.seg(
        contents,
        doc_matters,
      );
    } else if(doc_matters.opt_action_bool["html_seg"]) {
      mixin SiSUoutputHTML;
      auto html=SDPoutputHTML();
      html.css_write;
      html.seg(
        contents,
        doc_matters,
      );
    } else if(doc_matters.opt_action_bool["html_scroll"]) {
      mixin SiSUoutputHTML;
      auto html=SDPoutputHTML();
      html.css_write;
      html.scroll(
        contents,
        doc_matters,
      );
    }
    if (doc_matters.opt_action_bool["epub"]) {
      mixin SiSUoutputEPub;
      auto epub=SDPoutputEPub();
      epub.doc_content(         // consolidate
        contents,
        doc_matters,
      );
      // epub.css_write;
      // writeln("epub processing");
    }
    if (doc_matters.opt_action_bool["pdf"]) {
      /+ mixin SiSUoutputPDF; +/
      writeln("pdf processing");
    }
    if (doc_matters.opt_action_bool["odt"]) {
      /+ mixin SiSUoutputODT; +/
      writeln("odt processing");
    }
    if (doc_matters.opt_action_bool["sqlite"]) {
      /+ mixin SiSUoutputSQLite; +/
      writeln("sqlite processing");
    }
    if (doc_matters.opt_action_bool["postgresql"]) {
      /+ mixin SiSUoutputPostgreSQL; +/
      writeln("pgsql processing");
    }
  }
}