Cannot find protocol declaration

I have two view controllers A and B, and they both have each other as their delegates.

When I did nothing except define the protocols at the beginning of the header files and #import the other's header file, I got two errors along the lines of -

cannot find protocol declaration for "BDelegate", which was showing in A.h (where I wrote ) cannot find protocol declaration for "ADelegate", which was showing in B.h (where I wrote )

Looking online, people had written earlier that the circular inclusion of header files could be leading to the problems. They recommended either using #include instead, or @class declaration like -

@class A

instead of

#import A.h

inside #import B.h

I have tried almost every combination of these imports, and @classes, and #include but still can't get rid of the warnings. Also, solutions online recommended moving the #import to the .m files but that didn't help either. Part of the reason is that the solutions online are kinda fuzzy - if you could break it down that would be great.

Any suggestions about what can be done to fix this?

-- BigViewController.h --

#import "BaseViewController.h"
#include "BaseViewController.h"

@class BigViewController;

@protocol BigViewControllerDelegate
-(void) BigViewController:(BigViewController *) bigView;
@end

@interface BigViewController : UIViewController <BaseViewControllerDelegate>
{    
     //delegate
     id <BigViewControllerDelegate> delegate;

ivars...    
}

@properties...
@end

--------------------------------------------------

-- BaseViewController.h --

#<UIKit/UIKit.h>

#import "BigViewController.h"
#include "BigViewController.h"

@class BigViewController;

@protocol BaseViewControllerDelegate
- (void) setParametersWithItemChosen:(Item *) item;
@end

@interface BaseViewController : UIViewController <...BigViewControllerDelegate...>
{

   ivars...

   //delegate
    id <BaseViewControllerDelegate> delegate;
}

@properties...
@end