graph_base: add final keyword

Author: Mizux

ortools/graph_base/flow_graph.h

@@ -50,8 +50,8 @@ namespace util {
 // TODO(user): Currently only max-flow handles this graph, but not
 // min-cost-flow.
 template <typename NodeIndexType = int32_t, typename ArcIndexType = int32_t>
-class FlowGraph : public BaseGraph<FlowGraph<NodeIndexType, ArcIndexType>,
-                                   NodeIndexType, ArcIndexType, false> {
+class FlowGraph final : public BaseGraph<FlowGraph<NodeIndexType, ArcIndexType>,
+                                         NodeIndexType, ArcIndexType, false> {
   // Note that we do NOT use negated indices for reverse arc. So we use false
   // for the last template argument here HasNegativeReverseArcs.
   typedef BaseGraph<FlowGraph<NodeIndexType, ArcIndexType>, NodeIndexType,

ortools/graph_base/graph.h

@@ -36,7 +36,7 @@
 //   store them.
 //
 // Provided implementations:
-//   - ListGraph<> for the simplest api. Also aliased to util::Graph.
+//   - ListGraph<> for the simplest api.
 //   - StaticGraph<> for performance, but requires building before usage, see
 //     below
 //   - CompleteGraph<> if you need a fully connected graph
@@ -945,7 +945,7 @@ class ListGraph : public MutableGraph<ListGraph<NodeIndexType, ArcIndexType>,
 // StaticGraphWithoutTail<>. This almost corresponds to a past implementation
 // of StaticGraph<> @CL 116144340.
 template <typename NodeIndexType = int32_t, typename ArcIndexType = int32_t>
-class StaticGraph
+class StaticGraph final
     : public MutableGraph<StaticGraph<NodeIndexType, ArcIndexType>,
                           NodeIndexType, ArcIndexType, false> {
   typedef MutableGraph<StaticGraph<NodeIndexType, ArcIndexType>, NodeIndexType,
@@ -1172,7 +1172,7 @@ class ReverseArcListGraph
 // - The reverse arcs from a node are sorted by head (so we could add a log()
 //   time lookup function).
 template <typename NodeIndexType = int32_t, typename ArcIndexType = int32_t>
-class ReverseArcStaticGraph
+class ReverseArcStaticGraph final
     : public MutableGraph<ReverseArcStaticGraph<NodeIndexType, ArcIndexType>,
                           NodeIndexType, ArcIndexType, true> {
   static_assert(internal::IsSigned<ArcIndexType>(),

ortools/graph_base/topologicalsorter.h

@@ -56,7 +56,8 @@ namespace graph {
 
 // This is the recommended API when performance matters. It's also very simple.
 // AdjacencyList is any type that lets you iterate over the neighbors of
-// node with the [] operator, for example vector<vector<int>> or util::Graph.
+// node with the [] operator, for example vector<vector<int>> or
+// util::ListGraph.
 //
 // If you don't already have an adjacency list representation, build one using
 // StaticGraph<> in ./graph.h: FastTopologicalSort() can take any such graph as