/in/foo.cc: In function 'int main()':
/in/foo.cc:57:18: error: 'getfa' was not declared in this scope
   _1=getfa(b[i].x);
                  ^
/in/foo.cc:61:24: error: 'struct bian' has no member named 'v'
   DoubleAdd(_1,_2,b[i].v);
                        ^