test2

foo.h

#import <Foundation/Foundation.h>

class ObjectWrapper {
public:
  ObjectWrapper(id obj);

  id get();
  void set(id obj);

private:
  id obj_;
};


@interface Foo : NSObject
+ (ObjectWrapper)foo;
@end

foo.mm

#import "foo.h"


ObjectWrapper::ObjectWrapper(id obj)
  : obj_(obj) {
}

id ObjectWrapper::get() {
  return obj_;
}

void ObjectWrapper::set(id obj) {
  obj_ = obj;
}


@implementation Foo

+ (ObjectWrapper)foo {
  const char *status = (self == [Foo class]) ? "CORRECT" : "INCORRECT";
  NSLog(@"%s: receiver is %s", __func__, status);
  
  return ObjectWrapper{[[NSObject alloc] init]};
}

@end

Makefile

all: test2-arc-caller test2-mrr-caller
.PHONY: all

CXXFLAGS = -gdwarf -std=c++11
LDLIBS = -framework Foundation

test2-arc-caller: test2.mm foo.h foo.mm
	$(CXX) $(CXXFLAGS) -fobjc-arc -o test2-arc.o -c test2.mm
	$(CXX) $(CXXFLAGS) -fobjc-arc -o foo-arc.o -c foo.mm
	$(CXX) $(LDFLAGS) $(LDLIBS) -o $@ test2-arc.o foo-arc.o

test2-mrr-caller: test2.mm foo.h foo.mm
	$(CXX) $(CXXFLAGS) -fno-objc-arc -o test2-mrr.o -c test2.mm
	$(CXX) $(CXXFLAGS) -fobjc-arc -o foo-arc.o -c foo.mm
	$(CXX) $(LDFLAGS) $(LDLIBS) -o $@ test2-mrr.o foo-arc.o

clean:
	rm -rf test2-* *.o

.PHONY: clean

test2.mm

#import <Foundation/Foundation.h>

#import "foo.h"

int main() {
  @autoreleasepool {
    [Foo foo];
  }
}