I found one by accident with C++. It was a situation where class A had a protected field x, B inherited from A, and C was a friend of B. Can C access x? GCC an

I found one by accident with C++. It was a situation where class A had a protected field x, B inherited from A, and C was a friend of B. Can C access x? GCC and Clang disagreed on this. Upon close reading, Clang was right, C should be able to access x. (Why did I do this? C was a helper class for the purpose of running unit tests. Unit tests are supposed to poke around in stuff you wouldn't normally poke around in.)