/in/foo.cc: In function 'int main()':
/in/foo.cc:10:8: error: unable to find numeric literal operator 'operator""a'
  cout<<100a+10b+c;
        ^~~~
/in/foo.cc:10:8: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes
/in/foo.cc:10:13: error: unable to find numeric literal operator 'operator""b'
  cout<<100a+10b+c;
             ^~~
/in/foo.cc:10:13: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes