/in/foo.cc: In function 'char* getstr(int)':
/in/foo.cc:14:17: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
   case 1:return "L1";
                 ^~~~
/in/foo.cc:15:17: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
   case 2:return "L2";
                 ^~~~
/in/foo.cc:16:17: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
   case 3:return "R2";
                 ^~~~
/in/foo.cc:17:17: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
   case 4:return "R1";
                 ^~~~
/in/foo.cc:18:18: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
   default:return "";
                  ^~