Geoff Chappell - Software Analyst
positive:
/Op
negative:
/Op-
The positive and negative forms override each other, of course. Additionally, the /Op option is weakly implied by /Za and the /Op- option is weakly overridden by /Za.
The positive form passes to the front-end C and C++ compilers (C1 and C1XX) only. The negative form is not passed.