[Uleat]

I should follow-up and say that you can 'usually' get away with performing a Build without having to do a Clean beforehand.

Any time that you alter or remove a pre-decl/hint like that, it's possible the compiler will not pick up the reference change in the obj file.

If the unresolved external symbol error pops up after a change on code that has previously compiled, a Clean would be my first recommendation.

If the Clean does not resolve it, then there is a linkage error that needs to be addressed.

Usually, the only real problem you'll see by not performing a Clean with every build is bin bloat (artificially increased size of bins.)

Rare occasions, you can actually get errors.

I use the Build-only method on my dev code until I'm happy with its performance .. then do a full Clean-Build to make sure everything is still ok.