Fix MSVC warning C26814: "The const variable 'variable' can be computed at compile time. Consider using constexpr."

Author: SunBlack

apps/in_hand_scanner/src/icp.cpp

@@ -161,7 +161,7 @@ pcl::ihs::ICP::findTransformation(const MeshConstPtr& mesh_model,
 {
   // Check the input
   // TODO: Double check the minimum number of points necessary for icp
-  const std::size_t n_min = 4;
+  constexpr std::size_t n_min = 4;
 
   if (mesh_model->sizeVertices() < n_min || cloud_data->size() < n_min) {
     std::cerr << "ERROR in icp.cpp: Not enough input points!\n";

apps/in_hand_scanner/src/integration.cpp

@@ -124,7 +124,7 @@ pcl::ihs::Integration::reconstructMesh(const CloudXYZRGBNormalConstPtr& cloud_da
   // *   3 - 0  //
   const int offset_1 = -width;
   const int offset_2 = -width - 1;
-  const int offset_3 = -1;
+  constexpr int offset_3 = -1;
   const int offset_4 = -width - 2;
 
   for (int r = 1; r < height; ++r) {
@@ -262,7 +262,7 @@ pcl::ihs::Integration::merge(const CloudXYZRGBNormalConstPtr& cloud_data,
   // *   3 - 0  //
   const int offset_1 = -width;
   const int offset_2 = -width - 1;
-  const int offset_3 = -1;
+  constexpr int offset_3 = -1;
   const int offset_4 = -width - 2;
 
   const float dot_min = std::cos(max_angle_ * 17.45329252e-3); // deg to rad

apps/in_hand_scanner/src/main_window.cpp

@@ -70,7 +70,7 @@ pcl::ihs::MainWindow::MainWindow(QWidget* parent)
   spacer->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
   ui_->toolBar->insertWidget(ui_->actionHelp, spacer);
 
-  const double max = std::numeric_limits<double>::max();
+  constexpr double max = std::numeric_limits<double>::max();
 
   // In hand scanner
   QHBoxLayout* layout = new QHBoxLayout(ui_->placeholder_in_hand_scanner);

apps/in_hand_scanner/src/opengl_viewer.cpp

@@ -484,7 +484,7 @@ pcl::ihs::OpenGLViewer::addMesh(const CloudXYZRGBNormalConstPtr& cloud,
   const int h = cloud->height;
   const int offset_1 = -w;
   const int offset_2 = -w - 1;
-  const int offset_3 = -1;
+  constexpr int offset_3 = -1;
 
   FaceVertexMeshPtr mesh(new FaceVertexMesh());
   mesh->transformation = T;
@@ -1083,7 +1083,7 @@ pcl::ihs::OpenGLViewer::initializeGL()
 void
 pcl::ihs::OpenGLViewer::setupViewport(const int w, const int h)
 {
-  const float aspect_ratio = 4. / 3.;
+  constexpr float aspect_ratio = 4. / 3.;
 
   // Use the biggest possible area of the window to draw to
   //    case 1 (w < w_scaled):        case 2 (w >= w_scaled):

apps/point_cloud_editor/include/pcl/apps/point_cloud_editor/localTypes.h

@@ -167,25 +167,25 @@ struct IncIndex
 /// A helpful const representing the number of elements in our vectors.
 /// This is used for all operations that require the copying of the vector.
 /// Although this is used in a fairly generic way, the display requires 3D.
-const unsigned int XYZ_SIZE = 3;
+constexpr unsigned int XYZ_SIZE = 3;
 
 /// A helpful const representing the number of elements in each row/col in
 /// our matrices. This is used for all operations that require the copying of
 /// the matrix.
-const unsigned int MATRIX_SIZE_DIM = 4;
+constexpr unsigned int MATRIX_SIZE_DIM = 4;
 
 /// A helpful const representing the number of elements in our matrices.
 /// This is used for all operations that require the copying of the matrix.
-const unsigned int MATRIX_SIZE = MATRIX_SIZE_DIM * MATRIX_SIZE_DIM;
+constexpr unsigned int MATRIX_SIZE = MATRIX_SIZE_DIM * MATRIX_SIZE_DIM;
 
 /// The default window width
-const unsigned int WINDOW_WIDTH = 1200;
+constexpr unsigned int WINDOW_WIDTH = 1200;
 /// The default window height
-const unsigned int WINDOW_HEIGHT = 1000;
+constexpr unsigned int WINDOW_HEIGHT = 1000;
 
 /// The default z translation used to push the world origin in front of the
 /// display
-const float DISPLAY_Z_TRANSLATION = -2.0f;
+constexpr float DISPLAY_Z_TRANSLATION = -2.0f;
 
 /// The radius of the trackball given as a percentage of the screen width
-const float TRACKBALL_RADIUS_SCALE = 0.4f;
+constexpr float TRACKBALL_RADIUS_SCALE = 0.4f;

apps/src/feature_matching.cpp

@@ -324,7 +324,7 @@ ICCVTutorial<FeatureType>::findCorrespondences(
 
   // Find the index of the best match for each keypoint, and store it in
   // "correspondences_out"
-  const int k = 1;
+  constexpr int k = 1;
   pcl::Indices k_indices(k);
   std::vector<float> k_squared_distances(k);
   for (int i = 0; i < static_cast<int>(source->size()); ++i) {

apps/src/multiscale_feature_persistence_example.cpp

@@ -47,7 +47,7 @@
 using namespace pcl;
 
 const Eigen::Vector4f subsampling_leaf_size(0.01f, 0.01f, 0.01f, 0.0f);
-const float normal_estimation_search_radius = 0.05f;
+constexpr float normal_estimation_search_radius = 0.05f;
 
 void
 subsampleAndCalculateNormals(PointCloud<PointXYZ>::Ptr& cloud,

apps/src/openni_feature_persistence.cpp

@@ -69,11 +69,11 @@ using namespace std::chrono_literals;
   } while (false)
 // clang-format on
 
-const float default_subsampling_leaf_size = 0.02f;
-const float default_normal_search_radius = 0.041f;
+constexpr float default_subsampling_leaf_size = 0.02f;
+constexpr float default_normal_search_radius = 0.041f;
 const double aux[] = {0.21, 0.32};
 const std::vector<double> default_scales_vector(aux, aux + 2);
-const float default_alpha = 1.2f;
+constexpr float default_alpha = 1.2f;
 
 template <typename PointType>
 class OpenNIFeaturePersistence {

apps/src/openni_mobile_server.cpp

@@ -79,7 +79,7 @@ CopyPointCloudToBuffers(const pcl::PointCloud<pcl::PointXYZRGBA>::ConstPtr& clou
         point.x > bounds_max.x || point.y > bounds_max.y || point.z > bounds_max.z)
       continue;
 
-    const int conversion_factor = 500;
+    constexpr int conversion_factor = 500;
 
     cloud_buffers.points[j * 3 + 0] = static_cast<short>(point.x * conversion_factor);
     cloud_buffers.points[j * 3 + 1] = static_cast<short>(point.y * conversion_factor);

apps/src/openni_organized_edge_detection.cpp

@@ -68,7 +68,7 @@ class OpenNIOrganizedEdgeDetection {
                                      *this);
     viewer->resetCameraViewpoint("cloud");
 
-    const int point_size = 2;
+    constexpr int point_size = 2;
     viewer->addPointCloud<PointT>(cloud, "nan boundary edges");
     viewer->setPointCloudRenderingProperties(
         pcl::visualization::PCL_VISUALIZER_POINT_SIZE,