using _open and _setmode in visual studio 2015 on windows 10

Question

I'm trying to use the functions _open and _setmode from IO.h but can't seem to compile. I'm getting the following error:

error C3861: '_lsetmode': identifier not found

error C2065: '_open': undeclared identifier

What do I need to do to make sure I'm pointing to these functions?

Answer 1

I found the issue it was a conflicting include with another IO.h that is in my project.