foo.cpp: In constructor 'E::E(int, int, T, int)':
foo.cpp:25:21: warning: 'E::cost' will be initialized after [-Wreorder]
  int to,flow,next;T cost;
                     ^~~~
foo.cpp:25:14: warning:   'int E::next' [-Wreorder]
  int to,flow,next;T cost;
              ^~~~
foo.cpp:26:2: warning:   when initialized here [-Wreorder]
  E(int to=0,int flow=0,T cost=0,int next=0):to(to),flow(flow),cost(cost),next(next){}
  ^