[boost] [config] A question about BOOST_NO_NESTED_FRIENDSHIP

Hi, I've been merging my recent additions to the release branch and came across the BOOST_NO_NESTED_FRIENDSHIP macro, which hasn't been merged. Looking at its description and test, I'm not certain whether this macro actually flags a compiler deficiency, rather than valid behavior. Here's the description: If the compiler fails to support access to private members from nested classes And the test: class A { static int b; class B { int f() { return b; } }; }; To my understanding, 11.8 says that it shouldn't compile, as B doesn't have any privileged access to A::b. Am I missing something?