Inherit from c++ class

Question

Is it possible for an objective-c++ class to inherit a c++ class?
I have a TON of c++ code written, but need to incorporate that into an iPhone app.
For example, consider the following cpp and mm files:
// myCPlusPlus.cpp
myCPlusPlus
virtual int cPlusPlusMethod01(someClass obj1, someClass obj2) = 0;
// myObjcClass.mm
@interface myObjcClass : myCPlusPlus // <-------is this possible being that it's a c++ class?
@end
If that's not possible, what do you recommend? Write a wrapper?
thx,
Zakk

Answer 1

zakkhoyt wrote:
* Objective-C++ strives to allow C++ class instances to serve as instance variables. This is possible as long as the C++ class in question (along with all of its superclasses) does not have any virtual member functions defined. If any virtual member functions are present, the C++ class may not serve as an Objective-C instance variable.
So, it turns out that I still have a problem because the architecture of our code has many classes with pure virtual functions. What now? This figures.... It'll cover every problem except mine. I really really want to keep the class interface in tact.
Any other ideas (without having to rewrite any c++ code)?
You are misreading what that really means. It specifically says "instances", not "pointers". To quote that document:
#import <Cocoa/Cocoa.h>
struct Class0 { void foo(); };
struct Class1 { virtual void foo(); };
struct Class2 { Class2(int i, int j); };
@interface Foo : NSObject {
Class0 class0; // OK
Class1 class1; // ERROR!
Class1 *ptr; // OK—call 'ptr = new Class1()' from Foo's init,
// 'delete ptr' from Foo's dealloc
Class2 class2; // WARNING - constructor not called!
@end
class0 is an instance. That is OK because it has a default constructor and no virtual functions.
class1 is also an instance. This is not OK because it has a virtual function.
ptr is the same as class1, only it is a pointer instead of an instance. This is OK. See the comments above and my own, earlier reply.
class2 is out due to the constructor.
To wrap up, you are fine. Just write some wrappers.