Fix compilation issues on systems without std::filesystem (#23)

samples/rocjpeg_samples_utils.h

@@ -156,10 +156,19 @@ void RocJpegUtils::ParseCommandLine(std::string &input_path, std::string &output
 }
 
 bool RocJpegUtils::GetFilePaths(std::string &input_path, std::vector<std::string> &file_paths, bool &is_dir, bool &is_file) {
+#if __cplusplus >= 201703L && __has_include(<filesystem>)
     is_dir = std::filesystem::is_directory(input_path);
     is_file = std::filesystem::is_regular_file(input_path);
+#else
+    is_dir = std::experimental::filesystem::is_directory(input_path);
+    is_file = std::experimental::filesystem::is_regular_file(input_path);
+#endif
     if (is_dir) {
+#if __cplusplus >= 201703L && __has_include(<filesystem>)
         for (const auto &entry : std::filesystem::directory_iterator(input_path))
+#else
+        for (const auto &entry : std::experimental::filesystem::directory_iterator(input_path))
+#endif
             file_paths.push_back(entry.path());
     } else if (is_file) {
         file_paths.push_back(input_path);

src/rocjpeg_vaapi_decoder.cpp

@@ -499,7 +499,11 @@ void RocJpegVappiDecoder::GetVisibleDevices(std::vector<int>& visible_devices_ve
 void RocJpegVappiDecoder::GetCurrentComputePartition(std::vector<ComputePartition> &current_compute_partitions) {
     std::string search_path = "/sys/devices/";
     std::string partition_file = "current_compute_partition";
+#if __cplusplus >= 201703L && __has_include(<filesystem>)
     for (const auto& entry : std::filesystem::recursive_directory_iterator(search_path)) {
+#else
+    for (const auto& entry : std::experimental::filesystem::recursive_directory_iterator(search_path)) {
+#endif
         if (entry.path().filename() == partition_file) {
             std::ifstream file(entry.path());
             if (file.is_open()) {

src/rocjpeg_vaapi_decoder.h

@@ -31,7 +31,11 @@ THE SOFTWARE.
 #include <string>
 #include <fcntl.h>
 #include <unistd.h>
-#include <filesystem>
+#if __cplusplus >= 201703L && __has_include(<filesystem>)
+    #include <filesystem>
+#else
+    #include <experimental/filesystem>
+#endif
 #include <unordered_map>
 #include <memory>
 #include <va/va.h>