Used single quotes for single character in string::find algorithm, more efficient

src/Base/Interpreter.cpp

@@ -792,7 +792,7 @@ int getSWIGVersionFromModule(const std::string& module)
             Py::String file(mod.getAttr("__file__"));
             std::string filename = (std::string)file;
             // file can have the extension .py or .pyc
-            filename = filename.substr(0, filename.rfind("."));
+            filename = filename.substr(0, filename.rfind('.'));
             filename += ".py";
             boost::regex rx("^# Version ([1-9])\\.([0-9])\\.([0-9]+)");
             boost::cmatch what;

src/Base/Writer.cpp

@@ -317,7 +317,7 @@ void FileWriter::writeFiles(void)
         if (shouldWrite(entry.FileName, entry.Object)) {
             std::string filePath = entry.FileName;
             std::string::size_type pos = 0;
-            while ((pos = filePath.find("/", pos)) != std::string::npos) {
+            while ((pos = filePath.find('/', pos)) != std::string::npos) {
                 std::string dirName = DirName + "/" + filePath.substr(0, pos);
                 pos++;
                 Base::FileInfo fi(dirName);