you have to write those rules down in meticulous detail,... and at that point you're asking your contributors to study and internalize a large and complicated list of what is and isn't allowed
What about a short list of what is allowed, with a strict whitelisting policy? I recall from years ago a version of the Taligent C++ conventions that was fairly compact. (Which was also the subject of Bjarne Stroustrup's quip about trying to use C++ as "a poor man's Smalltalk.")
Automated tools that embody the blacklists might be useful here as well, provided that they can be scripted quickly. I'm not sure if there are parser-based tools for C++ that would fit the bill. The article's problems with non-empty constructors seem amenable to automated blacklisting. Unfortunately, even with such tools, this strategy entails lots of work up-front by project organizers.