[kentonv]

True, but that's a different level of ABI. Stefan is talking about the base language ABI, e.g. calling conventions, vtable layout, etc., which is what matters if you're trying to call C++ from another language. You're talking about the ABI of the standard library -- or, more accurately, any library that uses STL types in its interface (which probably disqualifies it from being called from another language anyway).