Make the save_getline private

src/swcio.hpp

@@ -211,10 +211,10 @@ public:
 
     std::istream &parse_record(std::istream &is, swc_record &record);
 
+private:
     // Getline version supporting both windows and linux line endings
     std::istream &safe_getline(std::istream& is, std::string& t);
 
-private:
     // Read the record from a string stream; will be treated like a single line
     swc_record parse_record(std::istringstream &is);