cmComputeComponentGraph: use `size_t` for component indices

This avoids using casts everywhere when dealing with the sizes.

1 files changed, 15 insertions, 12 deletions

diff --git a/Source/cmComputeComponentGraph.cxx b/Source/cmComputeComponentGraph.cxx
index 6826f23..16540c3 100644
--- a/Source/cmComputeComponentGraph.cxx
+++ b/Source/cmComputeComponentGraph.cxx
@@ -4,8 +4,11 @@
 
 #include <algorithm>
 #include <cassert>
+#include <cstddef>
+#include <limits>
 
-const int cmComputeComponentGraph::INVALID_COMPONENT = -1;
+const size_t cmComputeComponentGraph::INVALID_COMPONENT =
+  std::numeric_limits<size_t>::max();
 
 cmComputeComponentGraph::cmComputeComponentGraph(Graph const& input)
   : InputGraph(input)
@@ -27,7 +30,7 @@ void cmComputeComponentGraph::Compute()
 
 void cmComputeComponentGraph::Tarjan()
 {
-  int n = static_cast<int>(this->InputGraph.size());
+  size_t n = this->InputGraph.size();
   TarjanEntry entry = { 0, 0 };
   this->TarjanEntries.resize(0);
   this->TarjanEntries.resize(n, entry);
@@ -36,7 +39,7 @@ void cmComputeComponentGraph::Tarjan()
   this->TarjanWalkId = 0;
   this->TarjanVisited.resize(0);
   this->TarjanVisited.resize(n, 0);
-  for (int i = 0; i < n; ++i) {
+  for (size_t i = 0; i < n; ++i) {
     // Start a new DFS from this node if it has never been visited.
     if (!this->TarjanVisited[i]) {
       assert(this->TarjanStack.empty());
@@ -47,7 +50,7 @@ void cmComputeComponentGraph::Tarjan()
   }
 }
 
-void cmComputeComponentGraph::TarjanVisit(int i)
+void cmComputeComponentGraph::TarjanVisit(size_t i)
 {
   // We are now visiting this node.
   this->TarjanVisited[i] = this->TarjanWalkId;
@@ -61,7 +64,7 @@ void cmComputeComponentGraph::TarjanVisit(int i)
   // Follow outgoing edges.
   EdgeList const& nl = this->InputGraph[i];
   for (cmGraphEdge const& ni : nl) {
-    int j = ni;
+    size_t j = ni;
 
     // Ignore edges to nodes that have been reached by a previous DFS
     // walk.  Since we did not reach the current node from that walk
@@ -90,12 +93,12 @@ void cmComputeComponentGraph::TarjanVisit(int i)
   // Check if we have found a component.
   if (this->TarjanEntries[i].Root == i) {
     // Yes.  Create it.
-    int c = static_cast<int>(this->Components.size());
+    size_t c = this->Components.size();
     this->Components.emplace_back();
     NodeList& component = this->Components[c];
 
     // Populate the component list.
-    int j;
+    size_t j;
     do {
       // Get the next member of the component.
       j = this->TarjanStack.top();
@@ -118,13 +121,13 @@ void cmComputeComponentGraph::TransferEdges()
 {
   // Map inter-component edges in the original graph to edges in the
   // component graph.
-  int n = static_cast<int>(this->InputGraph.size());
-  for (int i = 0; i < n; ++i) {
-    int i_component = this->TarjanComponents[i];
+  size_t n = this->InputGraph.size();
+  for (size_t i = 0; i < n; ++i) {
+    size_t i_component = this->TarjanComponents[i];
     EdgeList const& nl = this->InputGraph[i];
     for (cmGraphEdge const& ni : nl) {
-      int j = ni;
-      int j_component = this->TarjanComponents[j];
+      size_t j = ni;
+      size_t j_component = this->TarjanComponents[j];
       if (i_component != j_component) {
         // We do not attempt to combine duplicate edges, but instead
         // store the inter-component edges with suitable multiplicity.