/in/foo.cc: In function 'float f(float)':
/in/foo.cc:11:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:16:37: warning: 'x' is used uninitialized in this function [-Wuninitialized]
 cout << setprecision(3)<<fixed<< f(x) << endl;
                                     ^