Make some global variables const (#531)

This change resolves all of the
cppcoreguidelines-avoid-non-const-global-variables warnings.

Author: vil02

benchmark/Utilities.hpp

@@ -83,9 +83,9 @@ static CXXGraph::Graph<int> *readGraph(const std::string &filename) {
 
 // Static Generation
 
-static auto nodes = generateRandomNodes(100000, 2);
-static auto edges = generateRandomEdges(100000, nodes);
-static auto undirectedEdges = generateRandomUndirectedEdges(100000, nodes);
-static auto cit_graph_ptr = readGraph("CitHepPh");
+static const auto nodes = generateRandomNodes(100000, 2);
+static const auto edges = generateRandomEdges(100000, nodes);
+static const auto undirectedEdges = generateRandomUndirectedEdges(100000, nodes);
+static const auto cit_graph_ptr = readGraph("CitHepPh");
 
 #endif  // __UTILITIES_H__

examples/PartitionExample/partition_example.cpp

@@ -13,7 +13,7 @@ static CXXGraph::Graph<int> *readGraph(const std::string &filename) {
   return graph_ptr;
 }
 
-static auto cit_graph_ptr = readGraph("CitHepPh");
+static const auto cit_graph_ptr = readGraph("CitHepPh");
 
 int main() {
   // std::cout << *cit_graph_ptr << std::endl;

test/PartitionTest.cpp

@@ -13,8 +13,8 @@ using shared = std::shared_ptr<T>;
 using std::make_shared;
 using std::make_unique;
 
-static auto nodes = generateRandomNodes(10000, 2);
-static auto edges = generateRandomEdges(10000, nodes);
+static const auto nodes = generateRandomNodes(10000, 2);
+static const auto edges = generateRandomEdges(10000, nodes);
 
 TEST(PartitionTest, test_1) {
   CXXGraph::Node<int> node1("1", 1);

test/RWOutputTest.cpp

@@ -52,8 +52,8 @@ generateRandomEdges(
   return edges;
 }
 
-static auto nodes = generateRandomNodes(10000, 2);
-static auto edges = generateRandomEdges(10000, nodes);
+static const auto nodes = generateRandomNodes(10000, 2);
+static const auto edges = generateRandomEdges(10000, nodes);
 
 //************* CSV ***************//