如何导入Objective-C ++文件

Question

I'm having trouble including a .mm file in my cocoa project. The .mm file #includes the .cpp file. If I don't #import the project builds fine. However, I need to #import the .mm file but when I do, I get 'string' file not found. How do I use the mm file without getting that error?

Here is a link to the project

Answer 1

Don't use #import with a .mm file. Move its public interface into a .h file and import that where you need it.

Answer 2

Turns out I needed to move the part of the interface that defines the cpp ivar to the implementation file CPPWrapper.mm

@interface CPPWrapper ()
@property (nonatomic, readwrite, assign) Cpp *cpp;
@end

@implementation CPPWrapper
@synthesize cpp = _cpp;
//do stuff with cpp ivar here
@end