Use always const reference in for-ranged loop instead of copying prim…

…itive data types

common/include/pcl/common/impl/centroid.hpp

@@ -135,7 +135,7 @@ pcl::compute3DCentroid (const pcl::PointCloud<PointT> &cloud,
   // If the data is dense, we don't need to check for NaN
   if (cloud.is_dense)
   {
-    for (const int index : indices)
+    for (const int &index : indices)
     {
       centroid[0] += cloud[index].x;
       centroid[1] += cloud[index].y;
@@ -149,7 +149,7 @@ pcl::compute3DCentroid (const pcl::PointCloud<PointT> &cloud,
   else
   {
     unsigned cp = 0;
-    for (const int index : indices)
+    for (const int &index : indices)
     {
       // Check if the point is invalid
       if (!isFinite (cloud [index]))
@@ -300,7 +300,7 @@ pcl::computeCovarianceMatrix (const pcl::PointCloud<PointT> &cloud,
   {
     point_count = 0;
     // For each point in the cloud
-    for (const int index : indices)
+    for (const int &index : indices)
     {
       // Check if the point is invalid
       if (!isFinite (cloud[index]))
@@ -434,7 +434,7 @@ pcl::computeCovarianceMatrix (const pcl::PointCloud<PointT> &cloud,
   if (cloud.is_dense)
   {
     point_count = static_cast<unsigned int> (indices.size ());
-    for (const int index : indices)
+    for (const int &index : indices)
     {
       //const PointT& point = cloud[*iIt];
       accu [0] += cloud[index].x * cloud[index].x;
@@ -448,7 +448,7 @@ pcl::computeCovarianceMatrix (const pcl::PointCloud<PointT> &cloud,
   else
   {
     point_count = 0;
-    for (const int index : indices)
+    for (const int &index : indices)
     {
       if (!isFinite (cloud[index]))
         continue;
@@ -562,7 +562,7 @@ pcl::computeMeanAndCovarianceMatrix (const pcl::PointCloud<PointT> &cloud,
   if (cloud.is_dense)
   {
     point_count = indices.size ();
-    for (const int index : indices)
+    for (const int &index : indices)
     {
       //const PointT& point = cloud[*iIt];
       accu [0] += cloud[index].x * cloud[index].x;
@@ -579,7 +579,7 @@ pcl::computeMeanAndCovarianceMatrix (const pcl::PointCloud<PointT> &cloud,
   else
   {
     point_count = 0;
-    for (const int index : indices)
+    for (const int &index : indices)
     {
       if (!isFinite (cloud[index]))
         continue;
@@ -886,10 +886,10 @@ pcl::computeCentroid (const pcl::PointCloud<PointInT>& cloud,
   pcl::CentroidPoint<PointInT> cp;
 
   if (cloud.is_dense)
-    for (const int index : indices)
+    for (const int &index : indices)
       cp.add (cloud[index]);
   else
-    for (const int index : indices)
+    for (const int &index : indices)
       if (pcl::isFinite (cloud[index]))
         cp.add (cloud[index]);
 

common/include/pcl/common/impl/common.hpp

@@ -86,7 +86,7 @@ pcl::getMeanStd (const std::vector<float> &values, double &mean, double &stddev)
 
   double sum = 0, sq_sum = 0;
 
-  for (const float value : values)
+  for (const float &value : values)
   {
     sum += value;
     sq_sum += value * value;
@@ -324,7 +324,7 @@ pcl::getMinMax3D (const pcl::PointCloud<PointT> &cloud, const pcl::PointIndices
   // If the data is dense, we don't need to check for NaN
   if (cloud.is_dense)
   {
-    for (const int index : indices.indices)
+    for (const int &index : indices.indices)
     {
       pcl::Array4fMapConst pt = cloud.points[index].getArray4fMap ();
       min_p = min_p.min (pt);
@@ -334,7 +334,7 @@ pcl::getMinMax3D (const pcl::PointCloud<PointT> &cloud, const pcl::PointIndices
   // NaN or Inf values could exist => check for them
   else
   {
-    for (const int index : indices.indices)
+    for (const int &index : indices.indices)
     {
       // Check if the point is invalid
       if (!std::isfinite (cloud.points[index].x) || 
@@ -361,7 +361,7 @@ pcl::getMinMax3D (const pcl::PointCloud<PointT> &cloud, const std::vector<int> &
   // If the data is dense, we don't need to check for NaN
   if (cloud.is_dense)
   {
-    for (const int index : indices)
+    for (const int &index : indices)
     {
       pcl::Array4fMapConst pt = cloud.points[index].getArray4fMap ();
       min_pt = min_pt.array ().min (pt);
@@ -371,7 +371,7 @@ pcl::getMinMax3D (const pcl::PointCloud<PointT> &cloud, const std::vector<int> &
   // NaN or Inf values could exist => check for them
   else
   {
-    for (const int index : indices)
+    for (const int &index : indices)
     {
       // Check if the point is invalid
       if (!std::isfinite (cloud.points[index].x) || 

common/src/common.cpp

@@ -74,7 +74,7 @@ pcl::getMeanStdDev (const std::vector<float> &values, double &mean, double &stdd
 {
   double sum = 0, sq_sum = 0;
 
-  for (const float value : values)
+  for (const float &value : values)
   {
     sum += value;
     sq_sum += value * value;