Make logger_ const pointer and modify SimulationLogger with const qualifiers as necessary

Author: aabrown100-git

Code/Source/solver/BoundaryCondition.h

@@ -80,7 +80,7 @@ class BoundaryCondition {
     using StringDoubleMap = std::map<std::string, double>;
 
     /// @brief Data members for BC
-    const faceType* face_ = nullptr;         ///< Face associated with the BC (can be null)
+    const faceType* face_ = nullptr;         ///< Face associated with the BC (not owned by BoundaryCondition)
     int global_num_nodes_ = 0;               ///< Global number of nodes on the face
     int local_num_nodes_ = 0;                ///< Local number of nodes on this processor
     std::vector<std::string> array_names_;   ///< Names of arrays to read from VTP file
@@ -91,7 +91,7 @@ class BoundaryCondition {
     std::string vtp_file_path_;              ///< Path to VTP file (empty if uniform)
     std::map<int, int> global_node_map_;     ///< Maps global node IDs to local array indices
     std::unique_ptr<VtkVtpData> vtp_data_;   ///< VTP data object
-    SimulationLogger* logger_ = nullptr;     ///< Logger for warnings/info
+    const SimulationLogger* logger_ = nullptr;  ///< Logger for warnings/info (not owned by BoundaryCondition)
 
 public:
     /// @brief Tolerance for point matching in VTP files

Code/Source/solver/SimulationLogger.h

@@ -47,7 +47,7 @@ class SimulationLogger {
       this->initialize(file_name, cout_write);
     }
 
-    void initialize(const std::string& file_name, bool cout_write=false) 
+    void initialize(const std::string& file_name, bool cout_write=false) const
     {
       log_file_.open(file_name);
       if (log_file_.fail()) {
@@ -65,7 +65,7 @@ class SimulationLogger {
       log_file_.close();
     }
 
-  template <class T> SimulationLogger& operator<< (const T& value)
+  template <class T> const SimulationLogger& operator<< (const T& value) const
   {
     if (file_name_ == "") { 
       return *this;
@@ -81,7 +81,7 @@ class SimulationLogger {
   }
 
   // Special handling for vector<string>
-  SimulationLogger& operator<< (const std::vector<std::string>& values)
+  const SimulationLogger& operator<< (const std::vector<std::string>& values) const
   {
     if (file_name_ == "") { 
       return *this;
@@ -101,7 +101,7 @@ class SimulationLogger {
     return *this;
   }
 
-  SimulationLogger& operator<<(std::ostream&(*value)(std::ostream& o))
+  const SimulationLogger& operator<<(std::ostream&(*value)(std::ostream& o)) const
   {
     if (file_name_ == "") { 
       return *this;
@@ -119,7 +119,7 @@ class SimulationLogger {
   /// @brief Log a message with automatic space separation
   /// @param args Arguments to log
   template<typename... Args>
-  SimulationLogger& log_message(const Args&... args) {
+  const SimulationLogger& log_message(const Args&... args) const {
     if (file_name_ == "") return *this;
 
     bool first = true;
@@ -129,10 +129,14 @@ class SimulationLogger {
   }
 
   private:
-    bool cout_write_ = false;
-    bool initialized_ = false;
-    std::string file_name_;
-    std::ofstream log_file_;
+    // These members are marked mutable because they can be modified in const member functions.
+    // While logging writes to a file (modifying these members), it doesn't change the logical
+    // state of the logger - this is exactly what mutable is designed for: implementation
+    // details that need to change even when the object's public state remains constant.
+    mutable bool cout_write_ = false;
+    mutable bool initialized_ = false;
+    mutable std::string file_name_;
+    mutable std::ofstream log_file_;
 };
 
 #endif