https://issues.dlang.org/show_bug.cgi?id=14363
--- Comment #3 from Kenji Hara <k.hara...@gmail.com> --- (In reply to Shammah Chancellor from comment #2) > Your code has a bug? > > return new B(5); > > Should be: > > return new B(); Yes. Sorry. > With that, your example compiles and works just fine on SDC. Hmm, interesting. SDC might use a thunk to get valid context pointer for base classes from the instantiated context. But it would need some runtime cost and additional vtbl entry. I don't have any knowledge about the SDC backend, but the ABI around nested classes would be different from dmd's. --