How to know a curve is outer edge or inner edge?

hi everyone.
Now i can get curve sources on a .step file, i want to know rules that the TopExp_Explorer class ergodic something like edge or face,
and how to know a curve on shape is outer edge or inner edge?

i'm sorry to my noob question,thanks guys

Eugene Zaliznyak's picture

You mean, does your edge belong to outer wire or inner wire of face? Sorry, I did not catch the meaning of question.