clang-tidy: remove invalid override from Boost visitor callbacks

Boost graph visitors use non-virtual template callbacks, so `override`
is not valid on these member functions. Remove `override` where the
base class does not declare virtual methods.

Fixes #3045

Author: sakirr

include/dagShortestPath/dagShortestPath.hpp

@@ -197,7 +197,7 @@ class Pgr_dag {
               m_goals(goals),
               m_n_goals(n_goals) {}
           template <class B_G>
-              void examine_vertex(V u, B_G &) override {
+              void examine_vertex(V u, B_G &) {
                   auto s_it = m_goals.find(u);
                   if (s_it == m_goals.end()) return;
 

include/visitors/astar_visitors.hpp

@@ -43,7 +43,7 @@ class astar_many_goals_visitor : public boost::default_astar_visitor {
      explicit astar_many_goals_visitor(const std::set<V> &goals)
          :m_goals(goals) {}
      template <class B_G>
-         void examine_vertex(V u, B_G &g) override {
+         void examine_vertex(V u, B_G &g) {
              auto s_it = m_goals.find(u);
              if (s_it == m_goals.end()) return;
              // found one more goal

include/visitors/dfs_visitor.hpp

@@ -59,13 +59,13 @@ class Dfs_visitor : public boost::default_dfs_visitor {
              m_depth.resize(m_graph.num_vertices(), 0);
          }
      template <typename B_G>
-         void start_vertex(V v, const B_G&) override {
+         void start_vertex(V v, const B_G&) {
              // exception for visitor termination
              if (v != m_roots) throw found_goals();
              m_depth[v] = 0;
          }
      template <typename B_G>
-         void examine_edge(E e, const B_G&) override {
+         void examine_edge(E e, const B_G&) {
              auto source = m_graph.source(e), target = m_graph.target(e);
              // If the target has not been visited before
              if (m_depth[target] == 0 && target != m_roots) {
@@ -79,7 +79,7 @@ class Dfs_visitor : public boost::default_dfs_visitor {
              }
          }
      template <typename B_G>
-         void tree_edge(E e, const B_G&) override {
+         void tree_edge(E e, const B_G&) {
              m_data.push_back(e);
          }
 

include/visitors/dfs_visitor_with_root.hpp

@@ -47,11 +47,11 @@ class Dfs_visitor_with_root : public boost::default_dfs_visitor {
          m_data(data),
          m_roots(root) {}
      template <typename B_G>
-         void tree_edge(E e, const B_G&) override {
+         void tree_edge(E e, const B_G&) {
              m_data.push_back(e);
          }
      template <typename B_G>
-         void start_vertex(V v, const B_G&) override {
+         void start_vertex(V v, const B_G&) {
              if (v != m_roots) throw found_goals();
          }
 

include/visitors/dijkstra_visitors.hpp

@@ -90,7 +90,7 @@ class dijkstra_many_goal_visitor : public boost::default_dijkstra_visitor {
          m_found_goals(f_goals)   {
          }
      template <class B_G>
-         void examine_vertex(V u, B_G &) override {
+         void examine_vertex(V u, B_G &) {
              auto s_it = m_goals.find(u);
 
              /* examined vertex is not a goal */
@@ -125,7 +125,7 @@ class dijkstra_distance_visitor : public boost::default_dijkstra_visitor {
              pgassert(m_distance_goal > 0);
          }
      template <class B_G>
-         void examine_vertex(V u, B_G &) override {
+         void examine_vertex(V u, B_G &) {
              if (m_dist[u] > m_distance_goal) {
                  throw found_goals();
              }
@@ -155,7 +155,7 @@ class dijkstra_distance_visitor_no_init : public boost::default_dijkstra_visitor
          }
 
      template <class B_G>
-         void examine_vertex(V u, B_G &) override {
+         void examine_vertex(V u, B_G &) {
              if ( 0 == m_num_examined++) m_root = u;
              if (m_dist[u] > m_distance_goal) {
                  throw found_goals();
@@ -166,22 +166,22 @@ class dijkstra_distance_visitor_no_init : public boost::default_dijkstra_visitor
          }
 
      template <class B_G>
-         void examine_edge(E e, B_G &g) override {
+         void examine_edge(E e, B_G &g) {
              if (source(e, g) != m_root && m_predecessors[source(e, g)] == source(e, g)) {
                  m_color[target(e, g)] = boost::black_color;
              }
          }
 
 
      template <class B_G>
-         void edge_not_relaxed(E e, B_G &g) override {
+         void edge_not_relaxed(E e, B_G &g) {
              if (source(e, g) != m_root && m_predecessors[source(e, g)] == source(e, g)) {
                  m_color[target(e, g)] = boost::black_color;
              }
          }
 
      template <class B_G>
-         void discover_vertex(V u, B_G &) override {
+         void discover_vertex(V u, B_G &) {
              if (u  != m_root && m_predecessors[u] == u) {
                  m_color[u] = boost::black_color;
              }

include/visitors/edges_order_bfs_visitor.hpp

@@ -44,7 +44,7 @@ class Edges_order_bfs_visitor : public boost::default_bfs_visitor {
              std::vector<E> &data) :
          m_data(data)  {}
      template <class B_G>
-         void tree_edge(E e, const B_G&) override {
+         void tree_edge(E e, const B_G&) {
              m_data.push_back(e);
          }
  private:

include/visitors/edges_order_dfs_visitor.hpp

@@ -45,7 +45,7 @@ class Edges_order_dfs_visitor : public boost::default_dfs_visitor {
              std::vector<E> &data) :
          m_data(data)  {}
      template <typename B_G>
-         void tree_edge(E e, const B_G&) override {
+         void tree_edge(E e, const B_G&) {
              m_data.push_back(e);
          }
  private:

include/visitors/prim_dijkstra_visitor.hpp

@@ -45,7 +45,7 @@ class Prim_dijkstra_visitor : public boost::default_dijkstra_visitor {
              std::vector<V> &data) :
          m_data(data)  {}
      template <class B_G>
-         void finish_vertex(V v, B_G&) override {
+         void finish_vertex(V v, B_G&) {
              m_data.push_back(v);
          }
  private: