imgui/examples/example_apple_metal/Shared/AppDelegate.h

#import <TargetConditionals.h>

#if TARGET_OS_IPHONE

#import <UIKit/UIKit.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@end

#else

#import <Cocoa/Cocoa.h>

@interface AppDelegate : NSObject <NSApplicationDelegate>
@end

#endif