Clang accepts invalid static_cast from derived type to private base type in case of rvalue reference (original) (raw)

Clang does not report any error for the following code:

struct A { int a;}; struct X : private A{};

int main() { X x; int a=static_cast<A&&>(x).a; }

Please note that this can be correctly rejected if the target type is not a rvalue reference.

GCC, EDG, and MSVC reject it:

Please see https://godbolt.org/z/aW1s6a7ec