/in/foo.cc: In function 'std::istream& operator>>(std::istream&, complexa&)':
/in/foo.cc:78:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'std::ostream& operator<<(std::ostream&, complexa&)':
/in/foo.cc:89:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^