Fix building with llvm-20 (#507)

* Make `Globals` class assignable

This class is currently intended to be assignable, but also has `const`
members which technically makes it not. Compilers like e.g., clang-20
check this and would reject the previous implementation.

* Bump testing dependency `madler/zlib`

Due to its minimum required 2.4 CMake version it was rejected by any
recent and supported CMake version. The previous implementation also
redefined macros set on e.g., macos-14.7 and would not build.

* Drop unused lambda captures

These are reported by e.g., clang-20.

* Add virtual destructors to polymorphic classes

Author: bbannier

include/CXXGraph/Graph/Algorithm/BestFirstSearch_impl.hpp

@@ -151,8 +151,8 @@ const std::vector<Node<T>> Graph<T>::concurrency_breadth_first_search(
   int block_size = 1;
   int level = 1;
 
-  auto extract_tasks = [&level_tracker, &tracker_mutex, &assigned_tasks,
-                        &num_tasks, &block_size]() -> std::pair<int, int> {
+  auto extract_tasks = [&assigned_tasks, &num_tasks,
+                        &block_size]() -> std::pair<int, int> {
     /*
     std::lock_guard<std::mutex> tracker_guard(tracker_mutex);
     int task_block_size = std::min(num_tasks - assigned_tasks,

include/CXXGraph/Graph/Algorithm/CycleDetection_impl.hpp

@@ -59,7 +59,7 @@ bool Graph<T>::isCyclicDirectedGraphDFS() const {
                          shared<const Node<T>>)>
           isCyclicDFSHelper;
       isCyclicDFSHelper =
-          [this, &isCyclicDFSHelper](
+          [&isCyclicDFSHelper](
               const std::shared_ptr<AdjacencyMatrix<T>> adjMatrix,
               std::unordered_map<CXXGraph::id_t, nodeStates> &states,
               shared<const Node<T>> node) {

include/CXXGraph/Graph/Algorithm/FordFulkerson_impl.hpp

@@ -67,7 +67,7 @@ double Graph<T>::fordFulkersonMaxFlow(const Node<T> &source,
       nodeSet.begin(), nodeSet.end(),
       [&target](auto node) { return node->getUserId() == target.getUserId(); });
 
-  auto bfs_helper = [this, &source_node_ptr, &target_node_ptr, &parent,
+  auto bfs_helper = [&source_node_ptr, &target_node_ptr, &parent,
                      &weightMap]() -> bool {
     std::unordered_map<shared<const Node<T>>, bool, nodeHash<T>> visited;
     std::queue<shared<const Node<T>>> queue;

include/CXXGraph/Graph/Algorithm/Kosaraju_impl.hpp

@@ -89,8 +89,8 @@ SCCResult<T> Graph<T>::kosaraju() const {
     visited.clear();
 
     std::function<void(shared<const Node<T>>, SCCResult<T>, int)> dfs_helper1 =
-        [this, &rev, &visited, &dfs_helper1](
-            shared<const Node<T>> source, SCCResult<T> result, int sccLabel) {
+        [&rev, &visited, &dfs_helper1](shared<const Node<T>> source,
+                                       SCCResult<T> result, int sccLabel) {
           // mark the vertex visited
           visited[source->getId()] = true;
           // Add the current vertex to the strongly connected

include/CXXGraph/Partitioning/PartitionState.hpp

@@ -40,6 +40,8 @@ namespace Partitioning {
 template <typename T>
 class PartitionState {
  public:
+  virtual ~PartitionState() = default;
+
   virtual shared<Record<T>> getRecord(CXXGraph::id_t x) = 0;
   virtual int getMachineLoad(const int m) const = 0;
   virtual int getMachineWeight(const int m) const = 0;

include/CXXGraph/Partitioning/PartitionStrategy.hpp

@@ -39,6 +39,8 @@ namespace Partitioning {
 template <typename T>
 class PartitionStrategy {
  public:
+  virtual ~PartitionStrategy() = default;
+
   virtual void performStep(shared<const Edge<T>> t,
                            shared<PartitionState<T>> Sstate) = 0;
 };

include/CXXGraph/Partitioning/Record.hpp

@@ -29,6 +29,8 @@ namespace Partitioning {
 template <typename T>
 class Record {
  public:
+  virtual ~Record() = default;
+
   virtual const std::set<int> &getPartitions() const = 0;
   virtual void addPartition(const int m) = 0;
   virtual bool hasReplicaInPartition(const int m) const = 0;
@@ -41,4 +43,4 @@ class Record {
 }  // namespace Partitioning
 }  // namespace CXXGraph
 
-#endif  // __CXXGRAPH_PARTITIONING_RECORD_H__
+#endif  // __CXXGRAPH_PARTITIONING_RECORD_H__

include/CXXGraph/Partitioning/Utility/Globals.hpp

@@ -41,8 +41,8 @@ class Globals {
   const std::string print() const;
 
   // CONSTANT
-  const int SLEEP_LIMIT = 16;  // In microseconds
-  const int PLACES = 4;
+  int SLEEP_LIMIT = 16;  // In microseconds
+  int PLACES = 4;
 
   int numberOfPartition = 0;  // number of partitions
   // OPTIONAL

include/CXXGraph/Utility/Runnable.hpp

@@ -25,6 +25,8 @@
 namespace CXXGraph {
 class Runnable {
  public:
+  virtual ~Runnable() = default;
+
   virtual void run() = 0;
 };
 }  // namespace CXXGraph

test/CMakeLists.txt

@@ -45,7 +45,7 @@ if(TEST)
     CPMAddPackage(
         NAME zlib
         GITHUB_REPOSITORY madler/zlib
-        VERSION 1.2.13
+        VERSION 1.3.1
         OPTIONS "CMAKE_POSITION_INDEPENDENT_CODE True"
     )