On 27 December 2010 13:16, ronny meeus wrote: > On Sun, Dec 26, 2010 at 5:21 PM, Jonathan Wakely <jwakely.gcc@xxxxxxxxx> wrote: >> >> You could put the next pointer in a separate struct which has no >> virtual functions, so it has the same layout in C and C++, then use >> that as a base class for a polymorphic C++ type. The C code >> manipulating the next pointer would only deal with the portable type. > > I understand this. The problem with this approach is that you force > your user to introduced an inheritance relationship with the > baseclass. If this needs to be introduced in an existing class > hierarchy it can introduce certain complexities. The code already has horrible, non-portable complexities. You have the option of replacing them with portable complexity. >> Or you could create an interface for manipulating the linked lists, >> compile the implementation as C++, and always modify the lists through >> that interface. > > I do not understand what you mean with an interface. > In Java we have interfaces but as far as I know, this concept does not > exists in C++. > If you mean just a class with abstract interfaces, I do not see what > the difference is with the base class approach mentioned above. I don't mean the Java keyword 'interface' I just mean an API which hides the implementation http://en.wikipedia.org/wiki/Interface_(computer_science) You could, for instance, declare functions to manipulate the pointers, and call those functions to add an a element to the linked list, instead of fiddling with raw memory everytime you want to manipulate a list.
