View Compilation Error

0_0_16987937_9936.cpp:1:2: error: expected unqualified-id before numeric constant
  1 struct Vector3{    //鏂瑰悜鍚戦噺 
  ^
0_0_16987937_9936.cpp:4:2: error: expected unqualified-id before numeric constant
  4 double xmulti3(Vector3 v1,Vector3 v2)    //涓夌淮鍚戦噺鐨勫弶绉� 
  ^