Unit testing non-exported classes in a DLL

Expanding on Tom Quarendon’s answer to this question, I have used a slight variant of Simon Steele’s response:

• Create a test project (using whatever test framework you like, I use CppUnit).
• In your test_case.cpp, #include <header/in/source/project.h>.
• In the test project properties:
  • In Linker->General, add the source project’s $(IntDir) to the Additional Library Directories.
  • In Linker->Input, add the .obj files to the Additional Dependencies.
• Add the dependency from the test project to the source project in Project->Project Dependencies.

Again, the only maintenance overhead is the standard one for unit tests – to create the dependency on the unit(s) you want to test.