Unit Testing a Library

Hi:

I've made a C++ library and would like to develop some unit test for
it. Do I need to make an executable to use unit tests or can I write
them against my dylib?

Also, what does it mean in the tutorial (http://developer.apple.com/
do***entation/DeveloperTools/Conceptual/UnitTesting/Articles/
CreatingTests.html#//apple_ref/doc/uid/TP40002171-122120) when it says
I need to register my tests? I suppose this depends on the answer to
my question above.

Thanks.