https://issues.dlang.org/show_bug.cgi?id=21690
--- Comment #4 from kinke <ki...@gmx.net> --- (In reply to thomas.bockman from comment #3) > Does that mean that passing a D-initialized extern(C++) class instance to > C++ code breaks dynamic casting on the C++ side, too? AFAIK, yes. > Given that all current D compilers are also C++ compilers They most definitely aren't - they are D compilers, with the ability to interop with C++ in many cases, but quite obviously not in all aspects. See point 33.1 and 33.13 on https://dlang.org/spec/cpp_interface.html. --