remove redundant code (file exists test)

library/phx/resources/resource_utils.cpp

@@ -28,6 +28,8 @@
 #include <string>
 #include <vector>
 
+#include "boost/filesystem.hpp"
+
 #include "phx/resources/resource_manager.hpp"
 #include "phx/resources_path.hpp"
 
@@ -81,14 +83,9 @@ std::string ResourceUtils::ExtractFileExtension(const std::string& file_name) {
 std::string ResourceUtils::FindFileInSearchPath(const std::string& file_name) {
   for (auto& entry : resource_search_paths_) {
     auto full_name = entry + file_name;
-    if (FileExists(full_name)) return full_name;
+    if (boost::filesystem::exists(full_name.c_str())) return full_name;
   }
   return "";
 }
 
-bool ResourceUtils::FileExists(const std::string& full_file_name) {
-  std::fstream target_file(full_file_name.c_str());
-  return target_file.is_open();
-}
-
 }  // namespace phx

library/phx/resources/resource_utils.hpp

@@ -72,7 +72,6 @@ class PHOENIX_EXPORT ResourceUtils final {
 
  private:
   static std::string FindFileInSearchPath(const std::string& file_name);
-  static bool FileExists(const std::string& full_file_name);
 
   static std::vector<std::string> resource_search_paths_;
 };