From de81593e987085f95ce823dd1a6db248156ae161 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Mon, 9 Jul 2018 19:15:46 -0400
Subject: [PATCH] Internals: Template GraphAlg to allow const. No functional
 change.

---
 src/V3GraphAlg.cpp | 12 ++++++------
 src/V3GraphAlg.h   | 18 ++++++++++--------
 src/V3GraphDfa.cpp |  6 +++---
 3 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/src/V3GraphAlg.cpp b/src/V3GraphAlg.cpp
index ac9b41b27..da908ecb5 100644
--- a/src/V3GraphAlg.cpp
+++ b/src/V3GraphAlg.cpp
@@ -74,7 +74,7 @@ void V3Graph::deleteCutableOnlyEdges() {
 //######################################################################
 // Algorithms - weakly connected components
 
-class GraphRemoveRedundant : GraphAlg {
+class GraphRemoveRedundant : GraphAlg<> {
     bool	m_sumWeights;		///< Sum, rather then maximize weights
 private:
     void main() {
@@ -138,7 +138,7 @@ void V3Graph::removeRedundantEdgesSum(V3EdgeFuncP edgeFuncp) {
 //######################################################################
 // Algorithms - weakly connected components
 
-class GraphAlgWeakly : GraphAlg {
+class GraphAlgWeakly : GraphAlg<> {
 private:
     void main() {
 	// Initialize state
@@ -183,7 +183,7 @@ void V3Graph::weaklyConnected(V3EdgeFuncP edgeFuncp) {
 //######################################################################
 // Algorithms - strongly connected components
 
-class GraphAlgStrongly : GraphAlg {
+class GraphAlgStrongly : GraphAlg<> {
 private:
     uint32_t	m_currentDfs;		// DFS count
     std::vector<V3GraphVertex*> m_callTrace;  // List of everything we hit processing so far
@@ -269,7 +269,7 @@ void V3Graph::stronglyConnected(V3EdgeFuncP edgeFuncp) {
 //######################################################################
 // Algorithms - ranking
 
-class GraphAlgRank : GraphAlg {
+class GraphAlgRank : GraphAlg<> {
 private:
     void main() {
 	// Rank each vertex, ignoring cutable edges
@@ -325,7 +325,7 @@ void V3Graph::rank(V3EdgeFuncP edgeFuncp) {
 //######################################################################
 // Algorithms - ranking
 
-class GraphAlgRLoops : GraphAlg {
+class GraphAlgRLoops : GraphAlg<> {
 private:
     std::vector<V3GraphVertex*> m_callTrace;  // List of everything we hit processing so far
     bool		   m_done;	// Exit algorithm
@@ -381,7 +381,7 @@ void V3Graph::reportLoops(V3EdgeFuncP edgeFuncp, V3GraphVertex* vertexp) {
 //######################################################################
 // Algorithms - subtrees
 
-class GraphAlgSubtrees : GraphAlg {
+class GraphAlgSubtrees : GraphAlg<> {
 private:
     V3Graph* m_loopGraphp;
 
diff --git a/src/V3GraphAlg.h b/src/V3GraphAlg.h
index d764ca9b5..63dc84516 100644
--- a/src/V3GraphAlg.h
+++ b/src/V3GraphAlg.h
@@ -30,17 +30,19 @@
 // Algorithms - common class
 // For internal use, most graph algorithms use this as a base class
 
+template <class T = V3Graph>  // Or sometimes const V3Graph
 class GraphAlg {
 protected:
-    V3Graph*	m_graphp;		// Graph we're operating upon
-    V3EdgeFuncP	m_edgeFuncp;		// Function that says we follow this edge
-
-    inline bool followEdge(V3GraphEdge* edgep) {
-	return (edgep->weight() && (m_edgeFuncp)(edgep));
-    }
-    GraphAlg(V3Graph* graphp, V3EdgeFuncP edgeFuncp)
-	: m_graphp(graphp), m_edgeFuncp(edgeFuncp) {}
+    T* m_graphp;  // Graph we're operating upon
+    V3EdgeFuncP m_edgeFuncp;  // Function that says we follow this edge
+    // CONSTRUCTORS
+    GraphAlg(T* graphp, V3EdgeFuncP edgeFuncp)
+        : m_graphp(graphp), m_edgeFuncp(edgeFuncp) {}
     ~GraphAlg() {}
+    // METHODS
+    inline bool followEdge(V3GraphEdge* edgep) {
+        return (edgep->weight() && (m_edgeFuncp)(edgep));
+    }
 };
 
 //============================================================================
diff --git a/src/V3GraphDfa.cpp b/src/V3GraphDfa.cpp
index f8fbd85cb..3914788b0 100644
--- a/src/V3GraphDfa.cpp
+++ b/src/V3GraphDfa.cpp
@@ -56,7 +56,7 @@ DfaVertex* DfaGraph::findStart() {
 // Algorithms - convert NFA to a DFA
 // Uses the Subset Construction Algorithm
 
-class GraphNfaToDfa : GraphAlg {
+class GraphNfaToDfa : GraphAlg<> {
     // We have two types of nodes in one graph, NFA and DFA nodes.
     // Edges from NFA to NFA come from the user, and indicate input or epsilon transitions
     // Edges from DFA to NFA indicate the NFA from which that DFA was formed.
@@ -363,7 +363,7 @@ void DfaGraph::nfaToDfa() {
 //
 // Scan the DFA, cleaning up trailing states.
 
-class DfaGraphReduce : GraphAlg {
+class DfaGraphReduce : GraphAlg<> {
 private:
     // METHODS
     static int debug() { return 0; }
@@ -505,7 +505,7 @@ void DfaGraph::dfaReduce() {
 // The user's old accept is now the new accept.  This is imporant as
 // we want the virtual type of it to be intact.
 
-class DfaGraphComplement : GraphAlg {
+class DfaGraphComplement : GraphAlg<> {
 private:
     // MEMBERS
     DfaVertex* m_tempNewerReject;