Stick to a Clearly Specified Subset of C++

It is often considered a good project management practice that only a clearly specified subset of C++ is allowed in the codebase.

As Item 1 of the Effective C++ states, C++ is a federation of languages. A related, well-known statement is that C++ is enormously complicated; practically no one can master the entire federation. So we all code a (different) subset of C++. The point is, a team should stick to only use a clearly specified subset of C++, a common denominator, that present and future members may grasp.

This all sounds good; however, C++ features are intertwined and sometimes force you to use either all or none of them. Take RAII (Resource Acquisition Is Initialization) for example. Since the only practical way in C++ to signal an error in constructor is through exception, if you want RAII, you are required to use exception, too. This is not an easy choice. Google chooses not to use both RAII and exception on the ground that writing exception-safe code is exceptionally hard, especially when they have an existing non-exception-safe codebase.

Also, it is hard to draw a clear borderline. We all agree that excessive template meta-programming is unmaintainable, but how much template witchcraft is considered excessive?

I don’t have a good guideline of choosing a C++ subset.