Wow, I hadn't heard of that one. It sounds very unpleasant. I have the exact opposite rule -- it should always be OK to include a header file on its own. As a

Wow, I hadn't heard of that one. It sounds very unpleasant. I have the exact opposite rule -- it should always be OK to include a header file on its own. As a corollary, headers must include or forward-declare everything they need.