Is it possible to Call the Objective- C++ classes and methods from the Objective C Class?
Already we have written a project with Objective C code. Now we have one C++ class to be integrated, So i thought to change only one Class to Objective C++ which interacts with native C++ Classes others will remain in Objective C. Is it possible? Could anyone can help me for better solution?
Thanks.
Yes, you can do that. As long as the interface of the class is C-ish, Objective-C doesn't care if the implementation is Objective-C or Objective-C++.
Yes. It's possible. Just hide C++ fields in extension. There is example:
//.h-file
@interface IntVector: NSObject
- (int) valueAtIndex:(NSUInteger) idx;
- (NSUInteger) size;
- (void) insertValue:(int) val atIndex:(NSUInteger) idx;
@end
//.mm-file
#include <vector>
using namespace std;
@interface IntVector()
{
vector<int> _vals;
}
@end
@implementation IntVector
- (int) valueAtIndex:(NSUInteger)idx
{
return _vals[idx];
}
- (NSUInteger) size
{
return _vals.size();
}
- (void) insertValue:(int) val atIndex:(NSUInteger) idx
{
_vals.indest(_vals.begin()+idx, val);
}
@end
You will be able use this class with any other objective-c code.
Yes, as long as you restrict your use of C++ types to the implementation file, you can call all of your ObjC++ classes from regular Objective C. There are a few gotchas, like wrapping any "loose" functions that you import in 'extern "C"' (like you would do when mixing C++ and straight C), but if you can assume a moderately recent version of Xcode (and don't need support for 32-bit MacOS), you can easily do all of that with a class extension (aka "class continuation").
If you want some tips and tricks about that topic, I was a guest on an episode of NSBrief a while ago where I talked at length about pretty much every aspect of using ObjC++: http://nsbrief.com/113-uli-kusterer/
You may also find an answer on this similar question: Can I separate C++ main function and classes from Objective-C and/or C routines at compile and link?
