[racket] Pattern patching and structures

Hello everyone,

I am using pattern matching and structures.
I have the following structure definition

(define-struct brick
   (shape cs size))

and the following function

(define (right brick)
   (match brick
     ((struct struct:brick (shape cs size))
      (make-brick shape (xy (- (x size) 1) (y size)) size))))

Why can't I use struct:brick in pattern matching?

Regards,
José

-- 
José António Branquinho de Oliveira Lopes
58612 - MEIC-A
jose.lopes at ist.utl.pt