/in/foo.cc: In function 'int main()':
/in/foo.cc:17:18: warning: 'a' is used uninitialized in this function [-Wuninitialized]
     cout<<s(a,b,c);
                  ^
/in/foo.cc:17:18: warning: 'b' is used uninitialized in this function [-Wuninitialized]
/in/foo.cc:17:18: warning: 'c' is used uninitialized in this function [-Wuninitialized]