Exploring @defs replacement in ObjC 2.0

test.m

/*
 * Compile with gcc -framework Foundation
 */

#import <Foundation/Foundation.h>

struct internals {
        int a;
        int b;
};

@interface Test : NSObject {
        struct internals internals_;
}

- (void *)internals;
- (void)printInternals;

@end

@implementation Test
- (void *)internals
{
        return &internals_;
}

- (void)printInternals
{
        NSLog(@"a = %d\tb = %d", internals_.a, internals_.b);
}

@end

int main(void)
{
        Test *test = [Test new];
        struct internals *a;
        a = [test internals];
        a->a = 1;
        a->b = 2;
        [test printInternals];
        NSLog(@"%p %p (%d)", test, a, (void *)a - (void *)test);

        return 0;
}