diff --git a/include/cgimap/api06/changeset_download_handler.hpp b/include/cgimap/api06/changeset_download_handler.hpp
index 474c4472..536db4cc 100644
--- a/include/cgimap/api06/changeset_download_handler.hpp
+++ b/include/cgimap/api06/changeset_download_handler.hpp
@@ -20,9 +20,6 @@ namespace api06 {
 class changeset_download_responder : public osmchange_responder {
 public:
   changeset_download_responder(mime::type, osm_changeset_id_t, data_selection &);
-
-private:
-  osm_changeset_id_t id;
 };
 
 class changeset_download_handler : public handler {
diff --git a/include/cgimap/api06/changeset_handler.hpp b/include/cgimap/api06/changeset_handler.hpp
index 13230fec..97f8d7c5 100644
--- a/include/cgimap/api06/changeset_handler.hpp
+++ b/include/cgimap/api06/changeset_handler.hpp
@@ -20,10 +20,6 @@ namespace api06 {
 class changeset_responder : public osm_current_responder {
 public:
   changeset_responder(mime::type, osm_changeset_id_t, bool, data_selection &);
-
-private:
-  osm_changeset_id_t id;
-  bool include_discussion;
 };
 
 class changeset_handler : public handler {
diff --git a/include/cgimap/api06/changeset_update_handler.hpp b/include/cgimap/api06/changeset_update_handler.hpp
index 1620178d..4f771776 100644
--- a/include/cgimap/api06/changeset_update_handler.hpp
+++ b/include/cgimap/api06/changeset_update_handler.hpp
@@ -26,9 +26,6 @@ class changeset_update_responder : public text_responder {
 			     osm_changeset_id_t id_,
                              const std::string & payload,
 			     std::optional<osm_user_id_t> user_id);
-
-private:
-  osm_changeset_id_t id;
 };
 
 class changeset_update_sel_responder : public osm_current_responder {
@@ -36,11 +33,8 @@ class changeset_update_sel_responder : public osm_current_responder {
   changeset_update_sel_responder(mime::type,
 			     data_selection & sel,
 			     osm_changeset_id_t id_);
-
 private:
   data_selection& sel;
-  osm_changeset_id_t id;
-  bool include_discussion;
 };
 
 class changeset_update_handler : public payload_enabled_handler {
diff --git a/include/cgimap/api06/node_handler.hpp b/include/cgimap/api06/node_handler.hpp
index 088a482b..4bc13422 100644
--- a/include/cgimap/api06/node_handler.hpp
+++ b/include/cgimap/api06/node_handler.hpp
@@ -22,9 +22,7 @@ class node_responder : public osm_current_responder {
   node_responder(mime::type, osm_nwr_id_t, data_selection &);
 
 private:
-  osm_nwr_id_t id;
-
-  void check_visibility();
+  void check_visibility(osm_nwr_id_t);
 };
 
 class node_handler : public handler {
diff --git a/include/cgimap/api06/node_history_handler.hpp b/include/cgimap/api06/node_history_handler.hpp
index 8f3b8138..c7210eff 100644
--- a/include/cgimap/api06/node_history_handler.hpp
+++ b/include/cgimap/api06/node_history_handler.hpp
@@ -19,9 +19,6 @@ namespace api06 {
 class node_history_responder : public osm_current_responder {
 public:
   node_history_responder(mime::type, osm_nwr_id_t, data_selection &);
-
-private:
-  osm_nwr_id_t id;
 };
 
 class node_history_handler : public handler {
diff --git a/include/cgimap/api06/node_relations_handler.hpp b/include/cgimap/api06/node_relations_handler.hpp
index 9bcd5332..bdac817c 100644
--- a/include/cgimap/api06/node_relations_handler.hpp
+++ b/include/cgimap/api06/node_relations_handler.hpp
@@ -22,9 +22,7 @@ class node_relations_responder : public osm_current_responder {
   node_relations_responder(mime::type, osm_nwr_id_t, data_selection &);
 
 private:
-  osm_nwr_id_t id;
-
-  bool is_visible();
+  bool is_visible(osm_nwr_id_t);
 };
 
 class node_relations_handler : public handler {
diff --git a/include/cgimap/api06/node_version_handler.hpp b/include/cgimap/api06/node_version_handler.hpp
index c2502dd6..0968b378 100644
--- a/include/cgimap/api06/node_version_handler.hpp
+++ b/include/cgimap/api06/node_version_handler.hpp
@@ -20,10 +20,6 @@ namespace api06 {
 class node_version_responder : public osm_current_responder {
 public:
   node_version_responder(mime::type, osm_nwr_id_t, osm_version_t, data_selection &);
-
-private:
-  osm_nwr_id_t id;
-  osm_nwr_id_t v;
 };
 
 class node_version_handler : public handler {
diff --git a/include/cgimap/api06/node_ways_handler.hpp b/include/cgimap/api06/node_ways_handler.hpp
index 76addbe1..f01aeb97 100644
--- a/include/cgimap/api06/node_ways_handler.hpp
+++ b/include/cgimap/api06/node_ways_handler.hpp
@@ -22,9 +22,7 @@ class node_ways_responder : public osm_current_responder {
   node_ways_responder(mime::type, osm_nwr_id_t, data_selection &);
 
 private:
-  osm_nwr_id_t id;
-
-  bool is_visible();
+  bool is_visible(osm_nwr_id_t);
 };
 
 class node_ways_handler : public handler {
diff --git a/include/cgimap/api06/nodes_handler.hpp b/include/cgimap/api06/nodes_handler.hpp
index a426f661..e86449a9 100644
--- a/include/cgimap/api06/nodes_handler.hpp
+++ b/include/cgimap/api06/nodes_handler.hpp
@@ -22,10 +22,7 @@ namespace api06 {
 
 class nodes_responder : public osm_current_responder {
 public:
-  nodes_responder(mime::type, std::vector<id_version>, data_selection &);
-
-private:
-  std::vector<id_version> ids;
+  nodes_responder(mime::type, const std::vector<id_version>&, data_selection &);
 };
 
 class nodes_handler : public handler {
diff --git a/include/cgimap/api06/relation_full_handler.hpp b/include/cgimap/api06/relation_full_handler.hpp
index f9fb2647..223ba6fd 100644
--- a/include/cgimap/api06/relation_full_handler.hpp
+++ b/include/cgimap/api06/relation_full_handler.hpp
@@ -22,9 +22,7 @@ class relation_full_responder : public osm_current_responder {
   relation_full_responder(mime::type, osm_nwr_id_t, data_selection &);
 
 private:
-  osm_nwr_id_t id;
-
-  void check_visibility();
+  void check_visibility(osm_nwr_id_t);
 };
 
 class relation_full_handler : public handler {
diff --git a/include/cgimap/api06/relation_handler.hpp b/include/cgimap/api06/relation_handler.hpp
index 1130bb57..1cf60398 100644
--- a/include/cgimap/api06/relation_handler.hpp
+++ b/include/cgimap/api06/relation_handler.hpp
@@ -22,9 +22,7 @@ class relation_responder : public osm_current_responder {
   relation_responder(mime::type, osm_nwr_id_t, data_selection &);
 
 private:
-  osm_nwr_id_t id;
-
-  void check_visibility();
+  void check_visibility(osm_nwr_id_t);
 };
 
 class relation_handler : public handler {
diff --git a/include/cgimap/api06/relation_history_handler.hpp b/include/cgimap/api06/relation_history_handler.hpp
index 0dcb9635..7566a0f0 100644
--- a/include/cgimap/api06/relation_history_handler.hpp
+++ b/include/cgimap/api06/relation_history_handler.hpp
@@ -19,9 +19,6 @@ namespace api06 {
 class relation_history_responder : public osm_current_responder {
 public:
   relation_history_responder(mime::type, osm_nwr_id_t, data_selection &);
-
-private:
-  osm_nwr_id_t id;
 };
 
 class relation_history_handler : public handler {
diff --git a/include/cgimap/api06/relation_relations_handler.hpp b/include/cgimap/api06/relation_relations_handler.hpp
index 35270ca0..f9bb87db 100644
--- a/include/cgimap/api06/relation_relations_handler.hpp
+++ b/include/cgimap/api06/relation_relations_handler.hpp
@@ -22,9 +22,7 @@ class relation_relations_responder : public osm_current_responder {
   relation_relations_responder(mime::type, osm_nwr_id_t, data_selection &);
 
 private:
-  osm_nwr_id_t id;
-
-  bool is_visible();
+  bool is_visible(osm_nwr_id_t);
 };
 
 class relation_relations_handler : public handler {
diff --git a/include/cgimap/api06/relation_version_handler.hpp b/include/cgimap/api06/relation_version_handler.hpp
index a2296473..7121c2d7 100644
--- a/include/cgimap/api06/relation_version_handler.hpp
+++ b/include/cgimap/api06/relation_version_handler.hpp
@@ -20,12 +20,6 @@ namespace api06 {
 class relation_version_responder : public osm_current_responder {
 public:
   relation_version_responder(mime::type, osm_nwr_id_t, osm_version_t v, data_selection &);
-
-private:
-  osm_nwr_id_t id;
-  osm_version_t v;
-
-  void check_visibility();
 };
 
 class relation_version_handler : public handler {
diff --git a/include/cgimap/api06/relations_handler.hpp b/include/cgimap/api06/relations_handler.hpp
index caae6399..6cffb2c0 100644
--- a/include/cgimap/api06/relations_handler.hpp
+++ b/include/cgimap/api06/relations_handler.hpp
@@ -23,10 +23,7 @@ namespace api06 {
 
 class relations_responder : public osm_current_responder {
 public:
-  relations_responder(mime::type, std::vector<id_version>, data_selection &);
-
-private:
-  std::vector<id_version> ids;
+  relations_responder(mime::type, const std::vector<id_version>&, data_selection &);
 };
 
 class relations_handler : public handler {
diff --git a/include/cgimap/api06/way_full_handler.hpp b/include/cgimap/api06/way_full_handler.hpp
index 8412c84d..cee95ba0 100644
--- a/include/cgimap/api06/way_full_handler.hpp
+++ b/include/cgimap/api06/way_full_handler.hpp
@@ -22,9 +22,7 @@ class way_full_responder : public osm_current_responder {
   way_full_responder(mime::type, osm_nwr_id_t, data_selection &);
 
 private:
-  osm_nwr_id_t id;
-
-  void check_visibility();
+  void check_visibility(osm_nwr_id_t id);
 };
 
 class way_full_handler : public handler {
diff --git a/include/cgimap/api06/way_handler.hpp b/include/cgimap/api06/way_handler.hpp
index b4ad7e5a..86bd4246 100644
--- a/include/cgimap/api06/way_handler.hpp
+++ b/include/cgimap/api06/way_handler.hpp
@@ -22,9 +22,7 @@ class way_responder : public osm_current_responder {
   way_responder(mime::type, osm_nwr_id_t, data_selection &);
 
 private:
-  osm_nwr_id_t id;
-
-  void check_visibility();
+  void check_visibility(osm_nwr_id_t);
 };
 
 class way_handler : public handler {
diff --git a/include/cgimap/api06/way_history_handler.hpp b/include/cgimap/api06/way_history_handler.hpp
index 5f6ba447..39dfc94b 100644
--- a/include/cgimap/api06/way_history_handler.hpp
+++ b/include/cgimap/api06/way_history_handler.hpp
@@ -19,9 +19,6 @@ namespace api06 {
 class way_history_responder : public osm_current_responder {
 public:
   way_history_responder(mime::type, osm_nwr_id_t, data_selection &);
-
-private:
-  osm_nwr_id_t id;
 };
 
 class way_history_handler : public handler {
diff --git a/include/cgimap/api06/way_relations_handler.hpp b/include/cgimap/api06/way_relations_handler.hpp
index ab15d495..84839c3e 100644
--- a/include/cgimap/api06/way_relations_handler.hpp
+++ b/include/cgimap/api06/way_relations_handler.hpp
@@ -22,9 +22,7 @@ class way_relations_responder : public osm_current_responder {
   way_relations_responder(mime::type, osm_nwr_id_t, data_selection &);
 
 private:
-  osm_nwr_id_t id;
-
-  bool is_visible();
+  bool is_visible(osm_nwr_id_t id);
 };
 
 class way_relations_handler : public handler {
diff --git a/include/cgimap/api06/way_version_handler.hpp b/include/cgimap/api06/way_version_handler.hpp
index 311b5eca..f0c3ce71 100644
--- a/include/cgimap/api06/way_version_handler.hpp
+++ b/include/cgimap/api06/way_version_handler.hpp
@@ -20,12 +20,6 @@ namespace api06 {
 class way_version_responder : public osm_current_responder {
 public:
   way_version_responder(mime::type, osm_nwr_id_t, osm_version_t, data_selection &);
-
-private:
-  osm_nwr_id_t id;
-  osm_version_t v;
-
-  void check_visibility();
 };
 
 class way_version_handler : public handler {
diff --git a/include/cgimap/api06/ways_handler.hpp b/include/cgimap/api06/ways_handler.hpp
index 129eaafb..8d9af0ee 100644
--- a/include/cgimap/api06/ways_handler.hpp
+++ b/include/cgimap/api06/ways_handler.hpp
@@ -22,10 +22,7 @@ namespace api06 {
 
 class ways_responder : public osm_current_responder {
 public:
-  ways_responder(mime::type, std::vector<id_version>, data_selection &);
-
-private:
-  std::vector<id_version> ids;
+  ways_responder(mime::type, const std::vector<id_version>&, data_selection &);
 };
 
 class ways_handler : public handler {
diff --git a/include/cgimap/api07/map_handler.hpp b/include/cgimap/api07/map_handler.hpp
index 9e911bd5..2ff6da95 100644
--- a/include/cgimap/api07/map_handler.hpp
+++ b/include/cgimap/api07/map_handler.hpp
@@ -27,21 +27,18 @@ namespace api07 {
 class map_responder : public osm_current_responder {
 public:
   map_responder(mime::type, bbox, data_selection &);
-  ~map_responder();
 };
 
 class map_handler : public handler {
 public:
   explicit map_handler(request &req);
   map_handler(request &req, int tile_id);
-  ~map_handler();
   std::string log_name() const override;
   responder_ptr_t responder(data_selection &x) const override;
 
 private:
   bbox bounds;
-
-  static bbox validate_request(request &req);
+  bbox validate_request(request &req);
 };
 
 } // namespace api07
diff --git a/src/api06/changeset_close_handler.cpp b/src/api06/changeset_close_handler.cpp
index 200ba5a2..c9ce0804 100644
--- a/src/api06/changeset_close_handler.cpp
+++ b/src/api06/changeset_close_handler.cpp
@@ -24,26 +24,21 @@
 namespace api06 {
 
 changeset_close_responder::changeset_close_responder(
-    mime::type mt, data_update & upd, osm_changeset_id_t id_, const std::string &payload,
+    mime::type mt, data_update & upd, osm_changeset_id_t changeset, const std::string &,
     std::optional<osm_user_id_t> user_id)
     : text_responder(mt) {
 
-  osm_changeset_id_t changeset = id_;
-  osm_user_id_t uid = *user_id;
-
-  auto changeset_updater = upd.get_changeset_updater(changeset, uid);
-
+  auto changeset_updater = upd.get_changeset_updater(changeset, *user_id);
   changeset_updater->api_close_changeset();
-
   upd.commit();
 }
 
 
 changeset_close_handler::changeset_close_handler(request &,
-                                                   osm_changeset_id_t id_)
+                                                   osm_changeset_id_t id)
     : payload_enabled_handler(mime::text_plain,
                               http::method::PUT | http::method::OPTIONS),
-      id(id_) {}
+      id(id) {}
 
 
 std::string changeset_close_handler::log_name() const {
@@ -58,8 +53,7 @@ changeset_close_handler::responder(data_selection &) const {
 
 responder_ptr_t changeset_close_handler::responder(
     data_update & upd, const std::string &payload, std::optional<osm_user_id_t> user_id) const {
-  return responder_ptr_t(
-      new changeset_close_responder(mime_type, upd, id, payload, user_id));
+  return std::make_unique<changeset_close_responder>(mime_type, upd, id, payload, user_id);
 }
 
 bool changeset_close_handler::requires_selection_after_update() const {
diff --git a/src/api06/changeset_create_handler.cpp b/src/api06/changeset_create_handler.cpp
index 158a7f87..762a138f 100644
--- a/src/api06/changeset_create_handler.cpp
+++ b/src/api06/changeset_create_handler.cpp
@@ -31,16 +31,11 @@ changeset_create_responder::changeset_create_responder(
 
   osm_changeset_id_t changeset = 0;
 
-  osm_user_id_t uid = *user_id;
-
-  auto changeset_updater = upd.get_changeset_updater(changeset, uid);
-
+  auto changeset_updater = upd.get_changeset_updater(changeset, *user_id);
   auto tags = ChangesetXMLParser().process_message(payload);
-
   changeset = changeset_updater->api_create_changeset(tags);
 
   output_text = std::to_string(changeset);
-
   upd.commit();
 }
 
@@ -60,8 +55,7 @@ changeset_create_handler::responder(data_selection &) const {
 
 responder_ptr_t changeset_create_handler::responder(
     data_update & upd, const std::string &payload, std::optional<osm_user_id_t> user_id) const {
-  return responder_ptr_t(
-      new changeset_create_responder(mime_type, upd, payload, user_id));
+  return std::make_unique<changeset_create_responder>(mime_type, upd, payload, user_id);
 }
 
 bool changeset_create_handler::requires_selection_after_update() const {
diff --git a/src/api06/changeset_download_handler.cpp b/src/api06/changeset_download_handler.cpp
index cf9dab15..dee3d134 100644
--- a/src/api06/changeset_download_handler.cpp
+++ b/src/api06/changeset_download_handler.cpp
@@ -17,8 +17,8 @@
 namespace api06 {
 
 changeset_download_responder::changeset_download_responder(
-  mime::type mt, osm_changeset_id_t id_, data_selection &w_)
-  : osmchange_responder(mt, w_), id(id_) {
+  mime::type mt, osm_changeset_id_t id, data_selection &w)
+  : osmchange_responder(mt, w) {
 
   if (sel.select_changesets({id}) == 0) {
     throw http::not_found(fmt::format("Changeset {:d} was not found.", id));
@@ -26,14 +26,14 @@ changeset_download_responder::changeset_download_responder(
   sel.select_historical_by_changesets({id});
 }
 
-changeset_download_handler::changeset_download_handler(request &req, osm_changeset_id_t id_)
-  : id(id_) {
+changeset_download_handler::changeset_download_handler(request &req, osm_changeset_id_t id)
+  : id(id) {
 }
 
 std::string changeset_download_handler::log_name() const { return "changeset/download"; }
 
 responder_ptr_t changeset_download_handler::responder(data_selection &w) const {
-  return responder_ptr_t(new changeset_download_responder(mime_type, id, w));
+  return std::make_unique<changeset_download_responder>(mime_type, id, w);
 }
 
 } // namespace api06
diff --git a/src/api06/changeset_handler.cpp b/src/api06/changeset_handler.cpp
index 3eb96e50..74d6be80 100644
--- a/src/api06/changeset_handler.cpp
+++ b/src/api06/changeset_handler.cpp
@@ -19,11 +19,10 @@ using std::vector;
 
 namespace api06 {
 
-changeset_responder::changeset_responder(mime::type mt, osm_changeset_id_t id_,
-                                         bool include_discussion_,
-                                         data_selection &w_)
-  : osm_current_responder(mt, w_), id(id_),
-    include_discussion(include_discussion_) {
+changeset_responder::changeset_responder(mime::type mt, osm_changeset_id_t id,
+                                         bool include_discussion,
+                                         data_selection &w)
+  : osm_current_responder(mt, w) {
 
   if (sel.select_changesets({id}) == 0) {
     throw http::not_found(fmt::format("Changeset {:d} was not found.", id));
@@ -34,26 +33,17 @@ changeset_responder::changeset_responder(mime::type mt, osm_changeset_id_t id_,
   }
 }
 
-namespace {
-// functor to use in find_if to locate the "include_discussion" header
-struct discussion_header_finder {
-  bool operator()(const std::pair<std::string, std::string> &header) const {
-    static const std::string target("include_discussion");
-    return header.first == target;
-  }
-};
-}
 
-changeset_handler::changeset_handler(request &req, osm_changeset_id_t id_)
-  : id(id_), include_discussion(false) {
-  using std::vector;
-  using std::pair;
-  using std::string;
+changeset_handler::changeset_handler(request &req, osm_changeset_id_t id)
+  : id(id), include_discussion(false) {
 
-  string decoded = http::urldecode(get_query_string(req));
-  const vector<pair<string, string> > params = http::parse_params(decoded);
+  std::string decoded = http::urldecode(get_query_string(req));
+  const auto params = http::parse_params(decoded);
   auto itr =
-    std::find_if(params.begin(), params.end(), discussion_header_finder());
+    std::find_if(params.begin(), params.end(),
+         [](const std::pair<std::string, std::string> &header) {
+               return (header.first == "include_discussion");
+  });
 
   include_discussion = (itr != params.end());
 }
@@ -62,7 +52,7 @@ changeset_handler::changeset_handler(request &req, osm_changeset_id_t id_)
 std::string changeset_handler::log_name() const { return "changeset"; }
 
 responder_ptr_t changeset_handler::responder(data_selection &w) const {
-  return responder_ptr_t(new changeset_responder(mime_type, id, include_discussion, w));
+  return std::make_unique<changeset_responder>(mime_type, id, include_discussion, w);
 }
 
 } // namespace api06
diff --git a/src/api06/changeset_update_handler.cpp b/src/api06/changeset_update_handler.cpp
index 86b25e5e..e1b4e7b2 100644
--- a/src/api06/changeset_update_handler.cpp
+++ b/src/api06/changeset_update_handler.cpp
@@ -29,16 +29,13 @@ namespace api06 {
 
 changeset_update_responder::changeset_update_responder(
     mime::type mt,
-    data_update & upd,
+    data_update &upd,
     osm_changeset_id_t changeset_id,
     const std::string &payload,
     std::optional<osm_user_id_t> user_id)
-    : text_responder(mt),
-      id(changeset_id){
+    : text_responder(mt){
 
-  osm_user_id_t uid = *user_id;
-
-  auto changeset_updater = upd.get_changeset_updater(changeset_id, uid);
+  auto changeset_updater = upd.get_changeset_updater(changeset_id, *user_id);
 
   auto tags = ChangesetXMLParser().process_message(payload);
 
@@ -49,21 +46,19 @@ changeset_update_responder::changeset_update_responder(
 
 changeset_update_sel_responder::changeset_update_sel_responder(
     mime::type mt,
-    data_selection & sel,
+    data_selection &sel,
     osm_changeset_id_t changeset_id)
     : osm_current_responder(mt, sel),
-      sel(sel),
-      id(changeset_id),
-      include_discussion(false){
+      sel(sel) {
 
   sel.select_changesets({changeset_id});
 }
 
 
-changeset_update_handler::changeset_update_handler(request &req, osm_changeset_id_t id_)
+changeset_update_handler::changeset_update_handler(request &req, osm_changeset_id_t id)
     : payload_enabled_handler(mime::application_xml,
                               http::method::PUT | http::method::OPTIONS),
-      id(id_) {}
+      id(id) {}
 
 std::string changeset_update_handler::log_name() const {
   return (fmt::format("changeset/update {:d}", id));
@@ -71,14 +66,12 @@ std::string changeset_update_handler::log_name() const {
 
 responder_ptr_t
 changeset_update_handler::responder(data_selection &sel) const {
-  return responder_ptr_t(
-      new changeset_update_sel_responder(mime_type, sel, id));
+  return std::make_unique<changeset_update_sel_responder>(mime_type, sel, id);
 }
 
 responder_ptr_t changeset_update_handler::responder(
     data_update & upd, const std::string &payload, std::optional<osm_user_id_t> user_id) const {
-  return responder_ptr_t(
-      new changeset_update_responder(mime_type, upd, id, payload, user_id));
+  return std::make_unique<changeset_update_responder>(mime_type, upd, id, payload, user_id);
 }
 
 bool changeset_update_handler::requires_selection_after_update() const {
diff --git a/src/api06/changeset_upload_handler.cpp b/src/api06/changeset_upload_handler.cpp
index 43538762..f43eea51 100644
--- a/src/api06/changeset_upload_handler.cpp
+++ b/src/api06/changeset_upload_handler.cpp
@@ -32,16 +32,13 @@
 namespace api06 {
 
 changeset_upload_responder::changeset_upload_responder(
-    mime::type mt, data_update& upd, osm_changeset_id_t id_, const std::string &payload,
+    mime::type mt, data_update& upd, osm_changeset_id_t changeset, const std::string &payload,
     std::optional<osm_user_id_t> user_id)
     : osm_diffresult_responder(mt) {
 
-  osm_changeset_id_t changeset = id_;
-  osm_user_id_t uid = *user_id;
-
   OSMChange_Tracking change_tracking{};
 
-  auto changeset_updater = upd.get_changeset_updater(changeset, uid);
+  auto changeset_updater = upd.get_changeset_updater(changeset, *user_id);
   auto node_updater = upd.get_node_updater(change_tracking);
   auto way_updater = upd.get_way_updater(change_tracking);
   auto relation_updater = upd.get_relation_updater(change_tracking);
@@ -61,13 +58,13 @@ changeset_upload_responder::changeset_upload_responder(
 
   if (global_settings::get_ratelimiter_upload()) {
 
-    auto max_changes = upd.get_rate_limit(uid);
+    auto max_changes = upd.get_rate_limit(*user_id);
     if (new_changes > max_changes)
     {
       logger::message(
           fmt::format(
               "Upload of {} changes by user {} in changeset {} blocked due to rate limiting, max. {} changes allowed",
-              new_changes, uid, changeset, max_changes));
+              new_changes, *user_id, changeset, max_changes));
       throw http::too_many_requests("Upload has been blocked due to rate limiting. Please try again later.");
     }
   }
@@ -78,10 +75,10 @@ changeset_upload_responder::changeset_upload_responder(
 }
 
 changeset_upload_handler::changeset_upload_handler(request &,
-                                                   osm_changeset_id_t id_)
+                                                   osm_changeset_id_t id)
     : payload_enabled_handler(mime::unspecified_type,
                               http::method::POST | http::method::OPTIONS),
-      id(id_) {}
+      id(id) {}
 
 std::string changeset_upload_handler::log_name() const {
   return (fmt::format("changeset/upload {:d}", id));
@@ -95,8 +92,7 @@ changeset_upload_handler::responder(data_selection &) const {
 
 responder_ptr_t changeset_upload_handler::responder(
     data_update & upd, const std::string &payload, std::optional<osm_user_id_t> user_id) const {
-  return responder_ptr_t(
-      new changeset_upload_responder(mime_type, upd, id, payload, user_id));
+  return std::make_unique<changeset_upload_responder>(mime_type, upd, id, payload, user_id);
 }
 
 bool changeset_upload_handler::requires_selection_after_update() const {
diff --git a/src/api06/map_handler.cpp b/src/api06/map_handler.cpp
index 8ac11b19..5c558853 100644
--- a/src/api06/map_handler.cpp
+++ b/src/api06/map_handler.cpp
@@ -72,14 +72,9 @@ string map_handler::log_name() const {
 }
 
 responder_ptr_t map_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new map_responder(mime_type, bounds, x));
+  return std::make_unique<map_responder>(mime_type, bounds, x);
 }
 
-namespace {
-bool is_bbox(const pair<string, string> &p) {
-  return p.first == "bbox";
-}
-} // anonymous namespace
 
 /**
  * Validates an FCGI request, returning the valid bounding box or
@@ -87,9 +82,10 @@ bool is_bbox(const pair<string, string> &p) {
  */
 bbox map_handler::validate_request(request &req) {
   string decoded = http::urldecode(get_query_string(req));
-  const vector<pair<string, string> > params = http::parse_params(decoded);
+  const auto params = http::parse_params(decoded);
   auto itr =
-    std::find_if(params.begin(), params.end(), is_bbox);
+    std::find_if(params.begin(), params.end(),
+        [](const pair<string, string> &p) { return p.first == "bbox"; });
 
   bbox bounds;
   if ((itr == params.end()) || !bounds.parse(itr->second)) {
diff --git a/src/api06/node_handler.cpp b/src/api06/node_handler.cpp
index d90e007b..20dc5d92 100644
--- a/src/api06/node_handler.cpp
+++ b/src/api06/node_handler.cpp
@@ -14,28 +14,29 @@
 
 namespace api06 {
 
-node_responder::node_responder(mime::type mt, osm_nwr_id_t id_, data_selection &w_)
-    : osm_current_responder(mt, w_), id(id_) {
+node_responder::node_responder(mime::type mt, osm_nwr_id_t id, data_selection &w)
+    : osm_current_responder(mt, w) {
 
   if (sel.select_nodes({id}) == 0) {
     throw http::not_found(fmt::format("Node {:d} was not found.", id));
   }
-  check_visibility();
+  check_visibility(id);
 }
 
-node_handler::node_handler(request &, osm_nwr_id_t id_) : id(id_) {}
+void node_responder::check_visibility(osm_nwr_id_t id) {
+  if (sel.check_node_visibility(id) == data_selection::deleted) {
+    // TODO: fix error message / throw structure to emit better error message
+    throw http::gone();
+  }
+}
+
+node_handler::node_handler(request &, osm_nwr_id_t id) : id(id) {}
 
 std::string node_handler::log_name() const { return "node"; }
 
 responder_ptr_t node_handler::responder(data_selection &w) const {
-  return responder_ptr_t(new node_responder(mime_type, id, w));
+  return std::make_unique<node_responder>(mime_type, id, w);
 }
 
-void node_responder::check_visibility() {
-  if (sel.check_node_visibility(id) == data_selection::deleted) {
-    // TODO: fix error message / throw structure to emit better error message
-    throw http::gone();
-  }
-}
 
 } // namespace api06
diff --git a/src/api06/node_history_handler.cpp b/src/api06/node_history_handler.cpp
index 4bbff053..a8e55c78 100644
--- a/src/api06/node_history_handler.cpp
+++ b/src/api06/node_history_handler.cpp
@@ -12,20 +12,20 @@
 
 namespace api06 {
 
-node_history_responder::node_history_responder(mime::type mt, osm_nwr_id_t id_, data_selection &w_)
-  : osm_current_responder(mt, w_), id(id_) {
+node_history_responder::node_history_responder(mime::type mt, osm_nwr_id_t id, data_selection &w)
+  : osm_current_responder(mt, w) {
 
   if (sel.select_nodes_with_history({id}) == 0) {
     throw http::not_found("");
   }
 }
 
-node_history_handler::node_history_handler(request &, osm_nwr_id_t id_) : id(id_) {}
+node_history_handler::node_history_handler(request &, osm_nwr_id_t id) : id(id) {}
 
 std::string node_history_handler::log_name() const { return "node/history"; }
 
 responder_ptr_t node_history_handler::responder(data_selection &w) const {
-  return responder_ptr_t(new node_history_responder(mime_type, id, w));
+  return std::make_unique<node_history_responder>(mime_type, id, w);
 }
 
 } // namespace api06
diff --git a/src/api06/node_relations_handler.cpp b/src/api06/node_relations_handler.cpp
index 779fbb58..e47c581f 100644
--- a/src/api06/node_relations_handler.cpp
+++ b/src/api06/node_relations_handler.cpp
@@ -12,26 +12,28 @@
 
 namespace api06 {
 
-node_relations_responder::node_relations_responder(mime::type mt, osm_nwr_id_t id_,
-                                         data_selection &w_)
-    : osm_current_responder(mt, w_), id(id_) {
+node_relations_responder::node_relations_responder(mime::type mt, osm_nwr_id_t id,
+                                         data_selection &w)
+    : osm_current_responder(mt, w) {
 
-  if (sel.select_nodes({id}) > 0 && is_visible()) {
+  if (sel.select_nodes({id}) > 0 && is_visible(id)) {
     sel.select_relations_from_nodes();
   }
   sel.drop_nodes();
 }
 
-node_relations_handler::node_relations_handler(request &, osm_nwr_id_t id_) : id(id_) {}
+bool node_relations_responder::is_visible(osm_nwr_id_t id) {
+  return (!(sel.check_node_visibility(id) == data_selection::deleted));
+}
+
+node_relations_handler::node_relations_handler(request &, osm_nwr_id_t id) : id(id) {}
 
 std::string node_relations_handler::log_name() const { return "node/relations"; }
 
 responder_ptr_t node_relations_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new node_relations_responder(mime_type, id, x));
+  return std::make_unique<node_relations_responder>(mime_type, id, x);
 }
 
-bool node_relations_responder::is_visible() {
-  return (!(sel.check_node_visibility(id) == data_selection::deleted));
-}
+
 
 } // namespace api06
diff --git a/src/api06/node_version_handler.cpp b/src/api06/node_version_handler.cpp
index e03fad62..f1160202 100644
--- a/src/api06/node_version_handler.cpp
+++ b/src/api06/node_version_handler.cpp
@@ -12,20 +12,20 @@
 
 namespace api06 {
 
-node_version_responder::node_version_responder(mime::type mt, osm_nwr_id_t id_, osm_version_t v_, data_selection &w_)
-    : osm_current_responder(mt, w_), id(id_), v(v_) {
+node_version_responder::node_version_responder(mime::type mt, osm_nwr_id_t id, osm_version_t v, data_selection &w)
+    : osm_current_responder(mt, w) {
 
   if (sel.select_historical_nodes({std::make_pair(id, v)}) == 0) {
      throw http::not_found("");
   }
 }
 
-node_version_handler::node_version_handler(request &, osm_nwr_id_t id_, osm_version_t v_) : id(id_), v(v_) {}
+node_version_handler::node_version_handler(request &, osm_nwr_id_t id, osm_version_t v) : id(id), v(v) {}
 
 std::string node_version_handler::log_name() const { return "node"; }
 
 responder_ptr_t node_version_handler::responder(data_selection &w) const {
-  return responder_ptr_t(new node_version_responder(mime_type, id, v, w));
+  return std::make_unique<node_version_responder>(mime_type, id, v, w);
 }
 
 } // namespace api06
diff --git a/src/api06/node_ways_handler.cpp b/src/api06/node_ways_handler.cpp
index 16c42992..cdb8c580 100644
--- a/src/api06/node_ways_handler.cpp
+++ b/src/api06/node_ways_handler.cpp
@@ -12,26 +12,27 @@
 
 namespace api06 {
 
-node_ways_responder::node_ways_responder(mime::type mt, osm_nwr_id_t id_,
-                                         data_selection &w_)
-    : osm_current_responder(mt, w_), id(id_) {
+node_ways_responder::node_ways_responder(mime::type mt, osm_nwr_id_t id,
+                                         data_selection &w)
+    : osm_current_responder(mt, w) {
 
-  if (sel.select_nodes({ id }) > 0 && is_visible()) {
+  if (sel.select_nodes({ id }) > 0 && is_visible(id)) {
     sel.select_ways_from_nodes();
   }
   sel.drop_nodes();
 }
 
-node_ways_handler::node_ways_handler(request &, osm_nwr_id_t id_) : id(id_) {}
+bool node_ways_responder::is_visible(osm_nwr_id_t id) {
+  return (!(sel.check_node_visibility(id) == data_selection::deleted));
+}
+
+node_ways_handler::node_ways_handler(request &, osm_nwr_id_t id) : id(id) {}
 
 std::string node_ways_handler::log_name() const { return "node/ways"; }
 
 responder_ptr_t node_ways_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new node_ways_responder(mime_type, id, x));
+  return std::make_unique<node_ways_responder>(mime_type, id, x);
 }
 
-bool node_ways_responder::is_visible() {
-  return (!(sel.check_node_visibility(id) == data_selection::deleted));
-}
 
 } // namespace api06
diff --git a/src/api06/nodes_handler.cpp b/src/api06/nodes_handler.cpp
index b22110a9..74879b1c 100644
--- a/src/api06/nodes_handler.cpp
+++ b/src/api06/nodes_handler.cpp
@@ -23,14 +23,14 @@ using std::string;
 
 namespace api06 {
 
-nodes_responder::nodes_responder(mime::type mt, vector<id_version> ids_,
-                                 data_selection &w_)
-    : osm_current_responder(mt, w_), ids(ids_) {
+nodes_responder::nodes_responder(mime::type mt, const vector<id_version> &ids,
+                                 data_selection &w)
+    : osm_current_responder(mt, w) {
 
   vector<osm_nwr_id_t> current_ids;
   vector<osm_edition_t> historic_ids;
 
-  for (id_version idv : ids_) {
+  for (const auto &idv : ids) {
     if (idv.version) {
       historic_ids.push_back(std::make_pair(idv.id, *idv.version));
     } else {
@@ -59,7 +59,7 @@ std::string nodes_handler::log_name() const {
 }
 
 responder_ptr_t nodes_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new nodes_responder(mime_type, ids, x));
+  return std::make_unique<nodes_responder>(mime_type, ids, x);
 }
 
 /**
diff --git a/src/api06/relation_full_handler.cpp b/src/api06/relation_full_handler.cpp
index b8d32d27..2a327abd 100644
--- a/src/api06/relation_full_handler.cpp
+++ b/src/api06/relation_full_handler.cpp
@@ -17,22 +17,23 @@ using std::vector;
 
 namespace api06 {
 
-relation_full_responder::relation_full_responder(mime::type mt_, osm_nwr_id_t id_,
-                                                 data_selection &w_)
-    : osm_current_responder(mt_, w_), id(id_) {
+relation_full_responder::relation_full_responder(mime::type mt_, osm_nwr_id_t id,
+                                                 data_selection &w)
+    : osm_current_responder(mt_, w) {
 
   if (sel.select_relations({id}) == 0) {
     throw http::not_found(fmt::format("Relation {:d} was not found.", id));
   }
 
-  check_visibility();
+  check_visibility(id);
   sel.select_nodes_from_relations();
   sel.select_ways_from_relations();
   sel.select_nodes_from_way_nodes();
   sel.select_relations_members_of_relations();
 }
 
-void relation_full_responder::check_visibility() {
+void relation_full_responder::check_visibility(osm_nwr_id_t id) {
+
   switch (sel.check_relation_visibility(id)) {
 
   case data_selection::non_exist:
@@ -47,8 +48,8 @@ void relation_full_responder::check_visibility() {
   }
 }
 
-relation_full_handler::relation_full_handler(request &, osm_nwr_id_t id_)
-    : id(id_) {
+relation_full_handler::relation_full_handler(request &, osm_nwr_id_t id)
+    : id(id) {
   logger::message(
       fmt::format("starting relation/full handler with id = {:d}", id));
 }
@@ -56,7 +57,7 @@ relation_full_handler::relation_full_handler(request &, osm_nwr_id_t id_)
 std::string relation_full_handler::log_name() const { return "relation/full"; }
 
 responder_ptr_t relation_full_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new relation_full_responder(mime_type, id, x));
+  return std::make_unique<relation_full_responder>(mime_type, id, x);
 }
 
 } // namespace api06
diff --git a/src/api06/relation_handler.cpp b/src/api06/relation_handler.cpp
index 629556c0..27cf6fd7 100644
--- a/src/api06/relation_handler.cpp
+++ b/src/api06/relation_handler.cpp
@@ -12,29 +12,30 @@
 
 namespace api06 {
 
-relation_responder::relation_responder(mime::type mt, osm_nwr_id_t id_,
-                                       data_selection &w_)
-    : osm_current_responder(mt, w_), id(id_) {
+relation_responder::relation_responder(mime::type mt, osm_nwr_id_t id,
+                                       data_selection &w)
+    : osm_current_responder(mt, w) {
 
   if (sel.select_relations({id}) == 0) {
     throw http::not_found(fmt::format("Relation {:d} was not found.", id));
   }
-  check_visibility();
+  check_visibility(id);
 }
 
-relation_handler::relation_handler(request &, osm_nwr_id_t id_) : id(id_) {}
+void relation_responder::check_visibility(osm_nwr_id_t id) {
+  if (sel.check_relation_visibility(id) == data_selection::deleted) {
+    // TODO: fix error message / throw structure to emit better error message
+    throw http::gone();
+  }
+}
+
+relation_handler::relation_handler(request &, osm_nwr_id_t id) : id(id) {}
 
 std::string relation_handler::log_name() const { return "relation"; }
 
 responder_ptr_t relation_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new relation_responder(mime_type, id, x));
+  return std::make_unique<relation_responder>(mime_type, id, x);
 }
 
-void relation_responder::check_visibility() {
-  if (sel.check_relation_visibility(id) == data_selection::deleted) {
-    // TODO: fix error message / throw structure to emit better error message
-    throw http::gone();
-  }
-}
 
 } // namespace api06
diff --git a/src/api06/relation_history_handler.cpp b/src/api06/relation_history_handler.cpp
index c92ad9fd..1ce74f81 100644
--- a/src/api06/relation_history_handler.cpp
+++ b/src/api06/relation_history_handler.cpp
@@ -12,20 +12,20 @@
 
 namespace api06 {
 
-relation_history_responder::relation_history_responder(mime::type mt, osm_nwr_id_t id_, data_selection &w_)
-  : osm_current_responder(mt, w_), id(id_) {
+relation_history_responder::relation_history_responder(mime::type mt, osm_nwr_id_t id, data_selection &w)
+  : osm_current_responder(mt, w) {
 
   if (sel.select_relations_with_history({id}) == 0) {
     throw http::not_found("");
   }
 }
 
-relation_history_handler::relation_history_handler(request &, osm_nwr_id_t id_) : id(id_) {}
+relation_history_handler::relation_history_handler(request &, osm_nwr_id_t id) : id(id) {}
 
 std::string relation_history_handler::log_name() const { return "relation/history"; }
 
 responder_ptr_t relation_history_handler::responder(data_selection &w) const {
-  return responder_ptr_t(new relation_history_responder(mime_type, id, w));
+  return std::make_unique<relation_history_responder>(mime_type, id, w);
 }
 
 } // namespace api06
diff --git a/src/api06/relation_relations_handler.cpp b/src/api06/relation_relations_handler.cpp
index f1023ed2..fc1a1554 100644
--- a/src/api06/relation_relations_handler.cpp
+++ b/src/api06/relation_relations_handler.cpp
@@ -12,27 +12,28 @@
 
 namespace api06 {
 
-relation_relations_responder::relation_relations_responder(mime::type mt, osm_nwr_id_t id_,
-                                         data_selection &w_)
-    : osm_current_responder(mt, w_), id(id_) {
+relation_relations_responder::relation_relations_responder(mime::type mt, osm_nwr_id_t id,
+                                         data_selection &w)
+    : osm_current_responder(mt, w) {
 
-  if (sel.select_relations({id}) > 0 && is_visible()) {
+  if (sel.select_relations({id}) > 0 && is_visible(id)) {
     sel.select_relations_from_relations(true);
   }
   else
     sel.drop_relations();
 }
 
-relation_relations_handler::relation_relations_handler(request &, osm_nwr_id_t id_) : id(id_) {}
+bool relation_relations_responder::is_visible(osm_nwr_id_t id) {
+  return (!(sel.check_relation_visibility(id) == data_selection::deleted));
+}
+
+relation_relations_handler::relation_relations_handler(request &, osm_nwr_id_t id) : id(id) {}
 
 std::string relation_relations_handler::log_name() const { return "relation/relations"; }
 
 responder_ptr_t relation_relations_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new relation_relations_responder(mime_type, id, x));
+  return std::make_unique<relation_relations_responder>(mime_type, id, x);
 }
 
-bool relation_relations_responder::is_visible() {
-  return (!(sel.check_relation_visibility(id) == data_selection::deleted));
-}
 
 } // namespace api06
diff --git a/src/api06/relation_version_handler.cpp b/src/api06/relation_version_handler.cpp
index d73113f7..350c843b 100644
--- a/src/api06/relation_version_handler.cpp
+++ b/src/api06/relation_version_handler.cpp
@@ -12,21 +12,21 @@
 
 namespace api06 {
 
-relation_version_responder::relation_version_responder(mime::type mt, osm_nwr_id_t id_, 
-                                       osm_version_t v_, data_selection &w_)
-    : osm_current_responder(mt, w_), id(id_), v(v_) {
+relation_version_responder::relation_version_responder(mime::type mt, osm_nwr_id_t id,
+                                       osm_version_t v, data_selection &w)
+    : osm_current_responder(mt, w) {
 
   if (sel.select_historical_relations({std::make_pair(id, v)}) == 0) {
      throw http::not_found("");
   }
 }
 
-relation_version_handler::relation_version_handler(request &, osm_nwr_id_t id_, osm_version_t v_) : id(id_), v(v_) {}
+relation_version_handler::relation_version_handler(request &, osm_nwr_id_t id, osm_version_t v) : id(id), v(v) {}
 
 std::string relation_version_handler::log_name() const { return "relation"; }
 
 responder_ptr_t relation_version_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new relation_version_responder(mime_type, id, v, x));
+  return std::make_unique<relation_version_responder>(mime_type, id, v, x);
 }
 
 } // namespace api06
diff --git a/src/api06/relations_handler.cpp b/src/api06/relations_handler.cpp
index 6f59c126..ee287660 100644
--- a/src/api06/relations_handler.cpp
+++ b/src/api06/relations_handler.cpp
@@ -23,13 +23,14 @@ using std::string;
 
 namespace api06 {
 
-relations_responder::relations_responder(mime::type mt, vector<id_version> ids_,
-                                         data_selection &s_)
-    : osm_current_responder(mt, s_), ids(ids_) {
+relations_responder::relations_responder(mime::type mt, const vector<id_version> &ids,
+                                         data_selection &s)
+    : osm_current_responder(mt, s) {
+
   vector<osm_nwr_id_t> current_ids;
   vector<osm_edition_t> historic_ids;
 
-  for (id_version idv : ids_) {
+  for (id_version idv : ids) {
     if (idv.version) {
       historic_ids.push_back(std::make_pair(idv.id, *idv.version));
     } else {
@@ -59,7 +60,7 @@ std::string relations_handler::log_name() const {
 }
 
 responder_ptr_t relations_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new relations_responder(mime_type, ids, x));
+  return std::make_unique<relations_responder>(mime_type, ids, x);
 }
 
 /**
diff --git a/src/api06/way_full_handler.cpp b/src/api06/way_full_handler.cpp
index 867f9395..e32fb4ff 100644
--- a/src/api06/way_full_handler.cpp
+++ b/src/api06/way_full_handler.cpp
@@ -16,18 +16,18 @@ using std::vector;
 
 namespace api06 {
 
-way_full_responder::way_full_responder(mime::type mt_, osm_nwr_id_t id_,
-                                       data_selection &w_)
-    : osm_current_responder(mt_, w_), id(id_) {
+way_full_responder::way_full_responder(mime::type mt, osm_nwr_id_t id,
+                                       data_selection &w)
+    : osm_current_responder(mt, w) {
 
   if (sel.select_ways({id}) == 0) {
     throw http::not_found(fmt::format("Way {:d} was not found.", id));
   }
-  check_visibility();
+  check_visibility(id);
   sel.select_nodes_from_way_nodes();
 }
 
-void way_full_responder::check_visibility() {
+void way_full_responder::check_visibility(osm_nwr_id_t id) {
   switch (sel.check_way_visibility(id)) {
 
   case data_selection::non_exist:
@@ -42,7 +42,7 @@ void way_full_responder::check_visibility() {
   }
 }
 
-way_full_handler::way_full_handler(request &, osm_nwr_id_t id_) : id(id_) {
+way_full_handler::way_full_handler(request &, osm_nwr_id_t id) : id(id) {
   logger::message(
       fmt::format("starting way/full handler with id = {:d}", id));
 }
@@ -50,7 +50,7 @@ way_full_handler::way_full_handler(request &, osm_nwr_id_t id_) : id(id_) {
 std::string way_full_handler::log_name() const { return "way/full"; }
 
 responder_ptr_t way_full_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new way_full_responder(mime_type, id, x));
+  return std::make_unique<way_full_responder>(mime_type, id, x);
 }
 
 } // namespace api06
diff --git a/src/api06/way_handler.cpp b/src/api06/way_handler.cpp
index 33ffa085..208796e6 100644
--- a/src/api06/way_handler.cpp
+++ b/src/api06/way_handler.cpp
@@ -14,28 +14,28 @@
 
 namespace api06 {
 
-way_responder::way_responder(mime::type mt, osm_nwr_id_t id_, data_selection &w_)
-    : osm_current_responder(mt, w_), id(id_) {
+way_responder::way_responder(mime::type mt, osm_nwr_id_t id, data_selection &w)
+    : osm_current_responder(mt, w) {
 
   if (sel.select_ways({id}) == 0) {
     throw http::not_found(fmt::format("Way {:d} was not found.", id));
   }
-  check_visibility();
+  check_visibility(id);
 }
 
-way_handler::way_handler(request &, osm_nwr_id_t id_) : id(id_) {}
-
-std::string way_handler::log_name() const { return "way"; }
-
-responder_ptr_t way_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new way_responder(mime_type, id, x));
-}
-
-void way_responder::check_visibility() {
+void way_responder::check_visibility(osm_nwr_id_t id) {
   if (sel.check_way_visibility(id) == data_selection::deleted) {
     // TODO: fix error message / throw structure to emit better error message
     throw http::gone();
   }
 }
 
+way_handler::way_handler(request &, osm_nwr_id_t id) : id(id) {}
+
+std::string way_handler::log_name() const { return "way"; }
+
+responder_ptr_t way_handler::responder(data_selection &x) const {
+  return std::make_unique<way_responder>(mime_type, id, x);
+}
+
 } // namespace api06
diff --git a/src/api06/way_history_handler.cpp b/src/api06/way_history_handler.cpp
index 4f110884..563b8ba8 100644
--- a/src/api06/way_history_handler.cpp
+++ b/src/api06/way_history_handler.cpp
@@ -12,20 +12,20 @@
 
 namespace api06 {
 
-way_history_responder::way_history_responder(mime::type mt, osm_nwr_id_t id_, data_selection &w_)
-  : osm_current_responder(mt, w_), id(id_) {
+way_history_responder::way_history_responder(mime::type mt, osm_nwr_id_t id, data_selection &w)
+  : osm_current_responder(mt, w) {
 
   if (sel.select_ways_with_history({id}) == 0) {
     throw http::not_found("");
   }
 }
 
-way_history_handler::way_history_handler(request &, osm_nwr_id_t id_) : id(id_) {}
+way_history_handler::way_history_handler(request &, osm_nwr_id_t id) : id(id) {}
 
 std::string way_history_handler::log_name() const { return "way/history"; }
 
 responder_ptr_t way_history_handler::responder(data_selection &w) const {
-  return responder_ptr_t(new way_history_responder(mime_type, id, w));
+  return std::make_unique<way_history_responder>(mime_type, id, w);
 }
 
 } // namespace api06
diff --git a/src/api06/way_relations_handler.cpp b/src/api06/way_relations_handler.cpp
index 7415e23e..bc1b5847 100644
--- a/src/api06/way_relations_handler.cpp
+++ b/src/api06/way_relations_handler.cpp
@@ -12,26 +12,28 @@
 
 namespace api06 {
 
-way_relations_responder::way_relations_responder(mime::type mt, osm_nwr_id_t id_,
-                                         data_selection &w_)
-    : osm_current_responder(mt, w_), id(id_) {
+way_relations_responder::way_relations_responder(mime::type mt, osm_nwr_id_t id,
+                                         data_selection &w)
+    : osm_current_responder(mt, w) {
 
-  if (sel.select_ways({id}) > 0 && is_visible()) {
+  if (sel.select_ways({id}) > 0 && is_visible(id)) {
     sel.select_relations_from_ways();
   }
   sel.drop_ways();
 }
 
-way_relations_handler::way_relations_handler(request &, osm_nwr_id_t id_) : id(id_) {}
+bool way_relations_responder::is_visible(osm_nwr_id_t id) {
+  return (!(sel.check_way_visibility(id) == data_selection::deleted));
+}
+
+
+way_relations_handler::way_relations_handler(request &, osm_nwr_id_t id) : id(id) {}
 
 std::string way_relations_handler::log_name() const { return "way/relations"; }
 
 responder_ptr_t way_relations_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new way_relations_responder(mime_type, id, x));
+  return std::make_unique<way_relations_responder>(mime_type, id, x);
 }
 
-bool way_relations_responder::is_visible() {
-  return (!(sel.check_way_visibility(id) == data_selection::deleted));
-}
 
 } // namespace api06
diff --git a/src/api06/way_version_handler.cpp b/src/api06/way_version_handler.cpp
index 9e2fde7c..5a721d36 100644
--- a/src/api06/way_version_handler.cpp
+++ b/src/api06/way_version_handler.cpp
@@ -14,20 +14,20 @@
 
 namespace api06 {
 
-way_version_responder::way_version_responder(mime::type mt, osm_nwr_id_t id_, osm_version_t v_, data_selection &w_)
-    : osm_current_responder(mt, w_), id(id_), v(v_) {
+way_version_responder::way_version_responder(mime::type mt, osm_nwr_id_t id, osm_version_t v, data_selection &w)
+    : osm_current_responder(mt, w) {
 
   if (sel.select_historical_ways({std::make_pair(id, v)}) == 0) {
      throw http::not_found("");
   }
 }
 
-way_version_handler::way_version_handler(request &, osm_nwr_id_t id_, osm_version_t v_) : id(id_), v(v_) {}
+way_version_handler::way_version_handler(request &, osm_nwr_id_t id, osm_version_t v) : id(id), v(v) {}
 
 std::string way_version_handler::log_name() const { return "way"; }
 
 responder_ptr_t way_version_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new way_version_responder(mime_type, id, v, x));
+  return std::make_unique<way_version_responder>(mime_type, id, v, x);
 }
 
 } // namespace api06
diff --git a/src/api06/ways_handler.cpp b/src/api06/ways_handler.cpp
index c5c7e970..9c387480 100644
--- a/src/api06/ways_handler.cpp
+++ b/src/api06/ways_handler.cpp
@@ -14,22 +14,18 @@
 #include "cgimap/infix_ostream_iterator.hpp"
 #include "cgimap/api06/id_version_io.hpp"
 
-
 #include <sstream>
 
-using std::stringstream;
-using std::vector;
-using std::string;
-
 namespace api06 {
 
-ways_responder::ways_responder(mime::type mt, vector<id_version> ids_,
-                               data_selection &w_)
-    : osm_current_responder(mt, w_), ids(ids_) {
-  vector<osm_nwr_id_t> current_ids;
-  vector<osm_edition_t> historic_ids;
+ways_responder::ways_responder(mime::type mt, const std::vector<id_version>& ids,
+                               data_selection &w)
+    : osm_current_responder(mt, w) {
+
+  std::vector<osm_nwr_id_t> current_ids;
+  std::vector<osm_edition_t> historic_ids;
 
-  for (id_version idv : ids_) {
+  for (id_version idv : ids) {
     if (idv.version) {
       historic_ids.push_back(std::make_pair(idv.id, *idv.version));
     } else {
@@ -50,7 +46,7 @@ ways_responder::ways_responder(mime::type mt, vector<id_version> ids_,
 ways_handler::ways_handler(request &req) : ids(validate_request(req)) {}
 
 std::string ways_handler::log_name() const {
-  stringstream msg;
+  std::stringstream msg;
   msg << "ways?ways=";
   std::copy(ids.begin(), ids.end(),
             infix_ostream_iterator<id_version>(msg, ", "));
@@ -58,15 +54,15 @@ std::string ways_handler::log_name() const {
 }
 
 responder_ptr_t ways_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new ways_responder(mime_type, ids, x));
+  return std::make_unique<ways_responder>(mime_type, ids, x);
 }
 
 /**
  * Validates an FCGI request, returning the valid list of ids or
  * throwing an error if there was no valid list of way ids.
  */
-vector<id_version> ways_handler::validate_request(request &req) {
-  vector<id_version> myids = parse_id_list_params(req, "ways");
+std::vector<id_version> ways_handler::validate_request(request &req) {
+  std::vector<id_version> myids = parse_id_list_params(req, "ways");
 
   if (myids.empty()) {
     throw http::bad_request(
diff --git a/src/api07/map_handler.cpp b/src/api07/map_handler.cpp
index 27ab47e2..2cb1ffcd 100644
--- a/src/api07/map_handler.cpp
+++ b/src/api07/map_handler.cpp
@@ -53,24 +53,19 @@ string map_handler::log_name() const {
 }
 
 responder_ptr_t map_handler::responder(data_selection &x) const {
-  return responder_ptr_t(new map_responder(mime_type, bounds, x));
+  return std::make_unique<map_responder>(mime_type, bounds, x);
 }
 
-namespace {
-bool is_bbox(const std::pair<string, string> &p) {
-  return p.first == "bbox";
-}
-} // anonymous namespace
-
 /**
  * Validates an FCGI request, returning the valid bounding box or
  * throwing an error if there was no valid bounding box.
  */
 bbox map_handler::validate_request(request &req) {
   string decoded = http::urldecode(get_query_string(req));
-  const std::vector<std::pair<string, string> > params = http::parse_params(decoded);
+  const auto params = http::parse_params(decoded);
   auto itr =
-    std::find_if(params.begin(), params.end(), is_bbox);
+    std::find_if(params.begin(), params.end(),
+        [](const pair<string, string> &p) { return p.first == "bbox"; });
 
   bbox bounds;
   if ((itr == params.end()) || !bounds.parse(itr->second)) {