Fix code messages

src/HoofIt.cpp

@@ -55,11 +55,11 @@ void HoofIt::finish()
 
     while (!queue.empty())
     {
-        auto trail = queue.front();
+        const auto& trail = queue.front();
         queue.pop();
         if (getCharAt(trail) != getTrailheadChar())
         {
-            for (auto direction : Point2::cardinalDirections)
+            for (const auto& direction : Point2::cardinalDirections)
             {
                 Point2 p{ trail + direction };
                 if (isInBounds(p) && getCharAt(p) + 1 == getCharAt(trail))
@@ -93,7 +93,7 @@ constexpr char HoofIt::getTrailTopChar()
 
 void HoofIt::addUnique(const std::vector<Point2>& source, std::vector<Point2>& destination)
 {
-    for (auto end : source)
+    for (const auto& end : source)
     {
         auto isUnique{ true };
         size_t i{ 0 };

src/ReindeerMaze.cpp

@@ -224,7 +224,7 @@ void ReindeerMaze::addCheckedIncidence(std::vector<ReindeerMazePathIncidence>& i
     }
 }
 
-Point2 ReindeerMaze::findStart()
+Point2 ReindeerMaze::findStart() const
 {
     for (int j = 0; j < lines.size(); j++)
     {

src/extra/MullData.cpp

@@ -20,7 +20,7 @@ MullData::MullData()
 {
 };
 
-bool MullData::getIsEnabled()
+bool MullData::getIsEnabled() const
 {
     return isEnabled_;
 }
@@ -30,7 +30,7 @@ void MullData::setIsEnabled(const bool value)
     isEnabled_ = value;
 }
 
-int MullData::getFactor(const int index)
+int MullData::getFactor(const int index) const
 {
     return index == 1 ? factor1_ : factor2_;
 }
@@ -57,12 +57,12 @@ void MullData::updateResult()
     }
 }
 
-long long int MullData::getResultPart1()
+long long int MullData::getResultPart1() const
 {
     return part1_;
 }
 
-long long int MullData::getResultPart2()
+long long int MullData::getResultPart2() const
 {
     return part2_;
 }

src/framework/SolverEngine.cpp

@@ -46,7 +46,7 @@ void SolverEngine::run(Solver& solver)
 
 std::filesystem::path SolverEngine::tryGetValidFullInputFilePath(const std::string& inputFileName)
 {
-    for (auto path : inputPaths_)
+    for (const auto& path : inputPaths_)
     {
         std::filesystem::path fullFilePath = path;
         fullFilePath /= inputFileName;