Update to use std::filesystem rather than Boost (#238)

This is intended to be a drop-in replacement for the functionality that
is currently in FilesystemBoost, as is demonstrated via no test updates.

Signed-off-by: Michael Carroll <[email protected]>
Co-authored-by: Louise Poubel <[email protected]>
Co-authored-by: Steve Peters <[email protected]>

examples/logging_performance.cc

@@ -42,7 +42,7 @@ void WriteToFile(std::string result_filename, std::string content)
     std::cerr << "Error writing to " << result_filename << std::endl;
   }
   out << content << std::flush;
-  std::cout << content;
+  //std::cout << content;
 }
 
 void MeasurePeakDuringLogWrites(const size_t id, std::vector<uint64_t> &result)

include/ignition/common/Filesystem.hh

@@ -264,9 +264,6 @@ namespace ignition
       /// \param[in] _in  Directory to iterate over.
       public: explicit DirIter(const std::string &_in);
 
-      /// \brief Destructor
-      public: ~DirIter();
-
       /// \brief Dereference operator; returns current directory record.
       /// \return A string representing the entire path of the directory
       /// record.
@@ -282,15 +279,6 @@ namespace ignition
       /// \return true if the iterators are equal, false otherwise.
       public: bool operator!=(const DirIter &_other) const;
 
-      /// \brief Move to the next directory record, skipping . and .. records.
-      private: void Next();
-
-      /// \brief Set the internal variable to the empty string.
-      private: void SetInternalEmpty();
-
-      /// \brief Close an open directory handle.
-      private: void CloseHandle();
-
       /// \brief Pointer to private data.
       IGN_UTILS_IMPL_PTR(dataPtr)
     };

include/ignition/common/SystemPaths.hh

@@ -17,16 +17,6 @@
 #ifndef IGNITION_COMMON_SYSTEMPATHS_HH_
 #define IGNITION_COMMON_SYSTEMPATHS_HH_
 
-#include <stdio.h>
-
-#ifdef _WIN32
-  #include <direct.h>
-  #define GetCurrentDir _getcwd
-#else
-  #include <unistd.h>
-  #define GetCurrentDir getcwd
-#endif
-
 #include <functional>
 #include <list>
 #include <string>
@@ -41,9 +31,6 @@ namespace ignition
 {
   namespace common
   {
-    // Forward declare private data class
-    class SystemPathsPrivate;
-
     /// \class SystemPaths SystemPaths.hh ignition/common/SystemPaths.hh
     /// \brief Functions to handle getting system paths, keeps track of:
     ///        \li SystemPaths#pluginPaths - plugin library paths

src/CMakeLists.txt

@@ -8,10 +8,17 @@ ign_create_core_library(
   SOURCES ${sources}
   CXX_STANDARD 17)
 
+if (CMAKE_CXX_COMPILER_ID STREQUAL GNU)
+    set(CXX_FILESYSTEM_LIBRARIES stdc++fs)
+else()
+    set(CXX_FILESYSTEM_LIBRARIES)
+endif()
+
 # Link the libraries that we always need
 target_link_libraries(${PROJECT_LIBRARY_TARGET_NAME} 
   PRIVATE 
     ${DL_TARGET}
+    ${CXX_FILESYSTEM_LIBRARIES}
   PUBLIC
     ignition-utils${IGN_UTILS_VER}::ignition-utils${IGN_UTILS_VER}
 )

src/DirIter.cc

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2021 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+*/
+
+#include <filesystem>
+
+#include "ignition/common/Filesystem.hh"
+
+namespace fs = std::filesystem;
+
+namespace ignition
+{
+namespace common
+{
+
+class DirIter::Implementation
+{
+  /// \brief Filesystem iterator that this class is wrapping
+  public: fs::directory_iterator it;
+};
+
+//////////////////////////////////////////////////
+DirIter::DirIter():
+  dataPtr(ignition::utils::MakeImpl<Implementation>())
+{
+  this->dataPtr->it = fs::directory_iterator();
+}
+
+//////////////////////////////////////////////////
+DirIter::DirIter(const std::string &_in):
+  DirIter()
+{
+  try
+  {
+    this->dataPtr->it = fs::directory_iterator(_in);
+  }
+  catch (const fs::filesystem_error &ex)
+  {
+  }
+}
+
+//////////////////////////////////////////////////
+std::string DirIter::operator*() const
+{
+  return this->dataPtr->it->path().string();
+}
+
+//////////////////////////////////////////////////
+const DirIter &DirIter::operator++()
+{
+  this->dataPtr->it++;
+  return *this;
+}
+
+//////////////////////////////////////////////////
+bool DirIter::operator!=(const DirIter &_other) const
+{
+  return (this->dataPtr->it != _other.dataPtr->it);
+}
+
+}  // namespace common
+}  // namespace ignition