Improve readability of string comparisons

apps/3d_rec_framework/include/pcl/apps/3d_rec_framework/pc_source/source.h

@@ -188,7 +188,7 @@ namespace pcl
             boost::split (strs, file, boost::is_any_of ("."));
             std::string extension = strs[strs.size () - 1];
 
-            if (extension.compare (ext) == 0)
+            if (extension == ext)
             {
               std::string path = rel_path_so_far + (itr->path ().filename ()).string();
 
@@ -229,7 +229,7 @@ namespace pcl
         typename std::vector<ModelT>::iterator it = models_->begin ();
         while (it != models_->end ())
         {
-          if (model_id.compare ((*it).id_) != 0)
+          if (model_id != (*it).id_)
           {
             it = models_->erase (it);
           }

apps/3d_rec_framework/include/pcl/apps/3d_rec_framework/pipeline/global_nn_recognizer_cvfh.h

@@ -94,7 +94,7 @@ namespace pcl
             else
             {
 
-              if (this->model.id_.compare (other.model.id_) == 0)
+              if (this->model.id_ == other.model.id_)
               {
                 //check view id
                 if ((this->view_id < other.view_id))

apps/3d_rec_framework/include/pcl/apps/3d_rec_framework/pipeline/impl/local_recognizer.hpp

@@ -105,7 +105,7 @@ template<template<class > class Distance, typename PointInT, typename FeatureT>
   {
     boost::shared_ptr < std::vector<ModelT> > models;
 
-    if(search_model_.compare("") == 0) {
+    if(search_model_.empty()) {
       models = source_->getModels ();
     } else {
       models = source_->getModels (search_model_);

apps/3d_rec_framework/src/tools/global_classification.cpp

@@ -168,7 +168,7 @@ main (int argc, char ** argv)
   normal_estimator->setRemoveOutliers (true);
   normal_estimator->setFactorsForCMR (3, 7);
 
-  if (desc_name.compare ("vfh") == 0)
+  if (desc_name == "vfh")
   {
     boost::shared_ptr<pcl::rec_3d_framework::VFHEstimation<pcl::PointXYZ, pcl::VFHSignature308> > vfh_estimator;
     vfh_estimator.reset (new pcl::rec_3d_framework::VFHEstimation<pcl::PointXYZ, pcl::VFHSignature308>);
@@ -188,7 +188,7 @@ main (int argc, char ** argv)
     segmentAndClassify<flann::L1, pcl::PointXYZ, pcl::VFHSignature308> (global);
   }
 
-  if (desc_name.compare ("cvfh") == 0)
+  if (desc_name == "cvfh")
   {
     boost::shared_ptr<pcl::rec_3d_framework::CVFHEstimation<pcl::PointXYZ, pcl::VFHSignature308> > vfh_estimator;
     vfh_estimator.reset (new pcl::rec_3d_framework::CVFHEstimation<pcl::PointXYZ, pcl::VFHSignature308>);
@@ -208,7 +208,7 @@ main (int argc, char ** argv)
     segmentAndClassify<Metrics::HistIntersectionUnionDistance, pcl::PointXYZ, pcl::VFHSignature308> (global);
   }
 
-  if (desc_name.compare ("esf") == 0)
+  if (desc_name == "esf")
   {
     boost::shared_ptr<pcl::rec_3d_framework::ESFEstimation<pcl::PointXYZ, pcl::ESFSignature640> > estimator;
     estimator.reset (new pcl::rec_3d_framework::ESFEstimation<pcl::PointXYZ, pcl::ESFSignature640>);

apps/3d_rec_framework/src/tools/local_recognition_mian_dataset.cpp

@@ -142,19 +142,19 @@ template<template<class > class DistT, typename PointT, typename FeatureT>
           g = 0.0f;
           b = 0.0f;
 
-          if (models->at (j).id_.compare ("cheff") == 0)
+          if (models->at (j).id_ == "cheff")
           {
             r = 0.0f;
             g = 255.0f;
             b = 0.0f;
           }
-          else if (models->at (j).id_.compare ("chicken_high") == 0)
+          else if (models->at (j).id_ == "chicken_high")
           {
             r = 0.0f;
             g = 255.0f;
             b = 255.0f;
           }
-          else if (models->at (j).id_.compare ("parasaurolophus_high") == 0)
+          else if (models->at (j).id_ == "parasaurolophus_high")
           {
             r = 255.0f;
             g = 255.0f;
@@ -260,7 +260,7 @@ getModelsInDirectory (bf::path & dir, std::string & rel_path_so_far, std::vector
       boost::split (strs, file, boost::is_any_of ("."));
       std::string extension = strs[strs.size () - 1];
 
-      if (extension.compare (ext) == 0)
+      if (extension == ext)
       {
         std::string path = rel_path_so_far + (itr->path ().filename ()).string();
 
@@ -318,13 +318,13 @@ main (int argc, char ** argv)
   pcl::console::parse_argument (argc, argv, "-use_hv", use_hv);
   pcl::console::parse_argument (argc, argv, "-thres_hyp", thres_hyp_);
 
-  if (mians_scenes.compare ("") == 0)
+  if (mians_scenes.empty())
   {
     PCL_ERROR("Set the directory containing mians scenes using the -mians_scenes_dir [dir] option\n");
     return -1;
   }
 
-  if (path.compare ("") == 0)
+  if (path.empty())
   {
     PCL_ERROR("Set the directory containing the models of mian dataset using the -models_dir [dir] option\n");
     return -1;
@@ -428,7 +428,7 @@ main (int argc, char ** argv)
       cast_hv_alg = boost::static_pointer_cast<pcl::HypothesisVerification<pcl::PointXYZ, pcl::PointXYZ> > (go);
   }
 
-  if (desc_name.compare ("shot") == 0)
+  if (desc_name == "shot")
   {
     boost::shared_ptr<pcl::rec_3d_framework::SHOTLocalEstimation<pcl::PointXYZ, pcl::Histogram<352> > > estimator;
     estimator.reset (new pcl::rec_3d_framework::SHOTLocalEstimation<pcl::PointXYZ, pcl::Histogram<352> >);
@@ -458,7 +458,7 @@ main (int argc, char ** argv)
 
   }
 
-  if (desc_name.compare ("shot_omp") == 0)
+  if (desc_name == "shot_omp")
   {
     desc_name = std::string ("shot");
     boost::shared_ptr<pcl::rec_3d_framework::SHOTLocalEstimationOMP<pcl::PointXYZ, pcl::Histogram<352> > > estimator;
@@ -492,7 +492,7 @@ main (int argc, char ** argv)
 
   }
 
-  if (desc_name.compare ("fpfh") == 0)
+  if (desc_name == "fpfh")
   {
     boost::shared_ptr<pcl::rec_3d_framework::FPFHLocalEstimation<pcl::PointXYZ, pcl::FPFHSignature33> > estimator;
     estimator.reset (new pcl::rec_3d_framework::FPFHLocalEstimation<pcl::PointXYZ, pcl::FPFHSignature33>);

apps/in_hand_scanner/src/offline_integration.cpp

@@ -190,7 +190,7 @@ pcl::ihs::OfflineIntegration::getFilesFromDirectory (const std::string
                                                      const std::string          extension,
                                                      std::vector <std::string>& files) const
 {
-  if (path_dir == "" || !boost::filesystem::exists (path_dir))
+  if (path_dir.empty() || !boost::filesystem::exists (path_dir))
   {
     std::cerr << "ERROR in offline_integration.cpp: Invalid path\n  '" << path_dir << "'\n";
     return (false);

apps/include/pcl/apps/face_detection/face_detection_apps_utils.h

@@ -89,7 +89,7 @@ namespace face_detection_apps_utils
         boost::split (strs, file, boost::is_any_of ("."));
         std::string extension = strs[strs.size () - 1];
 
-        if (extension.compare (ext) == 0)
+        if (extension == ext)
         {
           std::string path = rel_path_so_far + (itr->path().filename()).string();
           relative_paths.push_back (path);

apps/point_cloud_editor/src/cloudEditorWidget.cpp

@@ -132,7 +132,7 @@ CloudEditorWidget::save ()
   QString file_path = QFileDialog::getSaveFileName(this,tr("Save point cloud"));
 
   std::string file_path_std = file_path.toStdString();
-  if ( (file_path_std == "") || (!cloud_ptr_) )
+  if ( (file_path_std.empty()) || (!cloud_ptr_) )
     return;
 
   if (is_colored_)
@@ -577,7 +577,7 @@ CloudEditorWidget::isColored (const std::string &fileName) const
   {
     std::string name(field.name);
     stringToLower(name);
-    if ((name.compare("rgb") == 0) || (name.compare("rgba") == 0))
+    if ((name == "rgb") || (name == "rgba"))
       return true;
   }
   return false;

apps/point_cloud_editor/src/statistics.cpp

@@ -48,13 +48,13 @@ Statistics::getStats()
   for(const auto &stat_vec : stat_vec_)
   {
     std::string stat_string = stat_vec -> getStat();
-    if (stat_string != "")
+    if (!stat_string.empty())
     {
       result += (stat_string + '\n');
     }
   }
 
-  if (result == "")
+  if (result.empty())
     return ("Please load your cloud.");
   return (result);
 }

apps/src/face_detection/filesystem_face_detection.cpp

@@ -214,7 +214,7 @@ int main(int argc, char ** argv)
 
   pcl::visualization::PCLVisualizer vis ("PCL Face detection");
 
-  if (test_directory.compare ("") != 0)
+  if (!test_directory.empty())
   {
     //recognize all files in directory...
     std::string start;

apps/src/pcd_video_player/pcd_video_player.cpp

@@ -160,7 +160,7 @@ PCDVideoPlayer::selectFolderButtonPressed ()
     for (boost::filesystem::directory_iterator itr (dir_.toStdString ()); itr != end_itr; ++itr)
     {
       std::string ext = itr->path ().extension ().string ();
-      if (ext.compare (".pcd") == 0)
+      if (ext == ".pcd")
       {
         pcd_files_.push_back (itr->path ().string ());
         pcd_paths_.push_back (itr->path ());

cuda/apps/src/kinect_planes_cuda.cpp

@@ -275,7 +275,7 @@ class MultiRansac
       //bool repeat = false;
 
       //std::string path = "./pcl_logo.pcd";
-      //if (path != "" && boost::filesystem::exists (path))
+      //if (!path.empty() && boost::filesystem::exists (path))
       //{
       //  filegrabber = new pcl::PCDGrabber<pcl::PointXYZRGB > (path, frames_per_second, repeat);
       //}

geometry/include/pcl/geometry/mesh_io.h

@@ -103,7 +103,7 @@ namespace pcl
           unsigned int line_number = 1;
           int n_v = -1, n_he = -1, n_f = -1;
 
-          if (!std::getline (file, line) || line.compare ("PCL half-edge mesh") != 0)
+          if (!std::getline (file, line) || line != "PCL half-edge mesh")
           {
             std::cerr << "Error loading '" << filename << "' (line " << line_number << "): Wrong file format.\n";
             return (false);

io/src/depth_sense/depth_sense_grabber_impl.cpp

@@ -48,7 +48,7 @@ pcl::io::depth_sense::DepthSenseGrabberImpl::DepthSenseGrabberImpl (DepthSenseGr
 , color_data_ (COLOR_SIZE * 3)
 , depth_buffer_ (new pcl::io::SingleBuffer<float> (SIZE))
 {
-  if (device_id == "")
+  if (device_id.empty())
     device_id_ = DepthSenseDeviceManager::getInstance ()->captureDevice (this);
   else if (device_id[0] == '#')
     device_id_ = DepthSenseDeviceManager::getInstance ()->captureDevice (this, boost::lexical_cast<int> (device_id.substr (1)) - 1);

io/src/ifs_io.cpp

@@ -62,7 +62,7 @@ pcl::IFSReader::readHeader (const std::string &file_name, pcl::PCLPointCloud2 &c
   std::ifstream fs;
   std::string line;
 
-  if (file_name == "" || !boost::filesystem::exists (file_name))
+  if (file_name.empty() || !boost::filesystem::exists (file_name))
   {
     PCL_ERROR ("[pcl::IFSReader::readHeader] Could not find file '%s'.\n", file_name.c_str ());
     return (-1);

io/src/lzf_image_io.cpp

@@ -360,7 +360,7 @@ pcl::io::LZFImageReader::loadImageBlob (const std::string &filename,
                                         std::vector<char> &data,
                                         uint32_t &uncompressed_size)
 {
-  if (filename == "" || !boost::filesystem::exists (filename))
+  if (filename.empty() || !boost::filesystem::exists (filename))
   {
     PCL_ERROR ("[pcl::io::LZFImageReader::loadImage] Could not find file '%s'.\n", filename.c_str ());
     return (false);

io/src/obj_io.cpp

@@ -143,14 +143,14 @@ int
 pcl::MTLReader::read (const std::string& obj_file_name,
                       const std::string& mtl_file_name)
 {
-  if (obj_file_name == "" || !boost::filesystem::exists (obj_file_name))
+  if (obj_file_name.empty() || !boost::filesystem::exists (obj_file_name))
   {
     PCL_ERROR ("[pcl::MTLReader::read] Could not find file '%s'!\n",
                obj_file_name.c_str ());
     return (-1);
   }
 
-  if (mtl_file_name == "")
+  if (mtl_file_name.empty())
   {
     PCL_ERROR ("[pcl::MTLReader::read] MTL file name is empty!\n");
     return (-1);
@@ -165,7 +165,7 @@ pcl::MTLReader::read (const std::string& obj_file_name,
 int
 pcl::MTLReader::read (const std::string& mtl_file_path)
 {
-  if (mtl_file_path == "" || !boost::filesystem::exists (mtl_file_path))
+  if (mtl_file_path.empty() || !boost::filesystem::exists (mtl_file_path))
   {
     PCL_ERROR ("[pcl::MTLReader::read] Could not find file '%s'.\n", mtl_file_path.c_str ());
     return (-1);
@@ -192,7 +192,7 @@ pcl::MTLReader::read (const std::string& mtl_file_path)
     {
       getline (mtl_file, line);
       // Ignore empty lines
-      if (line == "")
+      if (line.empty())
         continue;
 
       // Tokenize the line
@@ -347,7 +347,7 @@ pcl::OBJReader::readHeader (const std::string &file_name, pcl::PCLPointCloud2 &c
   std::ifstream fs;
   std::string line;
 
-  if (file_name == "" || !boost::filesystem::exists (file_name))
+  if (file_name.empty() || !boost::filesystem::exists (file_name))
   {
     PCL_ERROR ("[pcl::OBJReader::readHeader] Could not find file '%s'.\n", file_name.c_str ());
     return (-1);
@@ -380,7 +380,7 @@ pcl::OBJReader::readHeader (const std::string &file_name, pcl::PCLPointCloud2 &c
     {
       getline (fs, line);
       // Ignore empty lines
-      if (line == "")
+      if (line.empty())
         continue;
 
       // Trim the line
@@ -548,7 +548,7 @@ pcl::OBJReader::read (const std::string &file_name, pcl::PCLPointCloud2 &cloud,
       std::string line;
       getline (fs, line);
       // Ignore empty lines
-      if (line == "")
+      if (line.empty())
         continue;
 
       // Tokenize the line
@@ -691,7 +691,7 @@ pcl::OBJReader::read (const std::string &file_name, pcl::TextureMesh &mesh,
     {
       getline (fs, line);
       // Ignore empty lines
-      if (line == "")
+      if (line.empty())
         continue;
 
       // Tokenize the line
@@ -782,7 +782,7 @@ pcl::OBJReader::read (const std::string &file_name, pcl::TextureMesh &mesh,
           }
         }
         // We didn't find the appropriate material so we create it here with name only.
-        if (mesh.tex_materials.back ().tex_name == "")
+        if (mesh.tex_materials.back ().tex_name.empty())
           mesh.tex_materials.back ().tex_name = st[1];
         mesh.tex_coordinates.push_back (coordinates);
         coordinates.clear ();
@@ -880,7 +880,7 @@ pcl::OBJReader::read (const std::string &file_name, pcl::PolygonMesh &mesh,
       std::string line;
       getline (fs, line);
       // Ignore empty lines
-      if (line == "")
+      if (line.empty())
         continue;
 
       // Tokenize the line

io/src/pcd_io.cpp

@@ -142,7 +142,7 @@ pcl::PCDReader::readHeader (std::istream &fs, pcl::PCLPointCloud2 &cloud,
     {
       getline (fs, line);
       // Ignore empty lines
-      if (line == "")
+      if (line.empty())
         continue;
 
       // Tokenize the line
@@ -380,7 +380,7 @@ pcl::PCDReader::readHeader (const std::string &file_name, pcl::PCLPointCloud2 &c
                             Eigen::Vector4f &origin, Eigen::Quaternionf &orientation, 
                             int &pcd_version, int &data_type, unsigned int &data_idx, const int offset)
 {
-  if (file_name == "" || !boost::filesystem::exists (file_name))
+  if (file_name.empty() || !boost::filesystem::exists (file_name))
   {
     PCL_ERROR ("[pcl::PCDReader::readHeader] Could not find file '%s'.\n", file_name.c_str ());
     return (-1);
@@ -442,7 +442,7 @@ pcl::PCDReader::readBodyASCII (std::istream &fs, pcl::PCLPointCloud2 &cloud, int
     {
       getline (fs, line);
       // Ignore empty lines
-      if (line == "")
+      if (line.empty())
         continue;
 
       // Tokenize the line
@@ -692,7 +692,7 @@ pcl::PCDReader::read (const std::string &file_name, pcl::PCLPointCloud2 &cloud,
   pcl::console::TicToc tt;
   tt.tic ();
 
-  if (file_name == "" || !boost::filesystem::exists (file_name))
+  if (file_name.empty() || !boost::filesystem::exists (file_name))
   {
     PCL_ERROR ("[pcl::PCDReader::read] Could not find file '%s'.\n", file_name.c_str ());
     return (-1);

io/src/real_sense_grabber.cpp

@@ -119,7 +119,7 @@ pcl::RealSenseGrabber::RealSenseGrabber (const std::string& device_id, const Mod
 , mode_requested_ (mode)
 , strict_ (strict)
 {
-  if (device_id == "")
+  if (device_id.empty())
     device_ = RealSenseDeviceManager::getInstance ()->captureDevice ();
   else if (device_id[0] == '#')
     device_ = RealSenseDeviceManager::getInstance ()->captureDevice (boost::lexical_cast<int> (device_id.substr (1)) - 1);

recognition/include/pcl/recognition/face_detection/face_detector_data_provider.h

@@ -55,7 +55,7 @@ namespace pcl
               boost::split (strs, file, boost::is_any_of ("."));
               std::string extension = strs[strs.size () - 1];
 
-              if (extension.compare (ext) == 0)
+              if (extension == ext)
               {
                 std::string path = rel_path_so_far + (itr->path ().filename ()).string ();
                 relative_paths.push_back (path);