I don't think that node is a POD type because it holds two reference members. More on this here: http://stackoverflow.com/questions/4178175/what-are-aggregates-

I don't think that node is a POD type because it holds two reference members. More on this here: http://stackoverflow.com/questions/4178175/what-are-aggregates-and-pods-and-how-why-are-they-special/7189821#7189821 http://stackoverflow.com/questions/4178175/what-are-aggregat... In particular, node does not have a trivial copy-assignment operator. Further below it seems that classes/structs containing references do not have a standard layout. Hence, it is not a POD. Also, the standard does not guarantee anything about your usage of reinterpret_cast. Maybe the code you provided works on your particular implementation, but I'm willing to bet that it violates the standard in several ways. EDIT: cool trick though. I forgot that a name is in scope and refers to itself just after it is declared, i.e., that you can refer to nil while constructing nil.