Use const (ref) variables for loops where possible

Author: joto

src/db-copy.cpp

@@ -31,7 +31,7 @@ void db_deleter_by_id_t::delete_rows(std::string const &table,
     fmt::format_to(std::back_inserter(sql),
                    FMT_STRING("DELETE FROM {} WHERE {} IN ("), table, column);
 
-    for (auto id : m_deletables) {
+    for (auto const id : m_deletables) {
         format_to(std::back_inserter(sql), FMT_STRING("{},"), id);
     }
     sql[sql.size() - 1] = ')';

src/geom-pole-of-inaccessibility.cpp

@@ -225,8 +225,8 @@ point_t pole_of_inaccessibility(const polygon_t &polygon, double precision,
         auto const h = cell.half_size / 2.0;
         auto const center = cell.center;
 
-        for (auto dy : {-h, h}) {
-            for (auto dx : {-h, h}) {
+        for (auto const dy : {-h, h}) {
+            for (auto const dx : {-h, h}) {
                 Cell const c{point_t{center.x() + dx, center.y() + dy}, h,
                              polygon, stretch};
                 if (c.max > best_cell.dist) {

src/middle-pgsql.cpp

@@ -1168,7 +1168,7 @@ void middle_pgsql_t::stop()
     if (m_options->droptemp) {
         // Dropping the tables is fast, so do it synchronously to guarantee
         // that the space is freed before creating the other indices.
-        for (auto &table : m_tables) {
+        for (auto const &table : m_tables) {
             table.drop_table(m_db_connection);
         }
     } else if (!m_options->append) {

src/output-flex.cpp

@@ -1258,7 +1258,7 @@ output_flex_t::output_flex_t(std::shared_ptr<middle_query_t> const &mid,
         m_table_connections.emplace_back(&table, m_copy_thread);
     }
 
-    for (auto &expire_output : *m_expire_outputs) {
+    for (auto const &expire_output : *m_expire_outputs) {
         m_expire_tiles.emplace_back(
             expire_output.maxzoom(),
             reprojection::create_projection(PROJ_SPHERE_MERC));

src/output-pgsql.cpp

@@ -366,7 +366,7 @@ void output_pgsql_t::delete_from_output_and_expire(osmid_t id)
 {
     m_tables[t_roads]->delete_row(id);
 
-    for (auto table : {t_line, t_poly}) {
+    for (auto const table : {t_line, t_poly}) {
         if (m_expire.enabled()) {
             auto const results = m_tables.at(table)->get_wkb(id);
             if (expire_from_result(&m_expire, results, m_expire_config) != 0) {