! Unit Test: { [ "m1x" ] [ Cb new m1 ] }
! fails.
! A ROLE tree doesn't seem to provide method overriding?

IN: exploring-workaround
USING: kernel prettyprint tools.test ;
USE: roles
FROM: roles => TUPLE: ;

ROLE: Cxr ;
ROLE: Car ;
TUPLE: Ca <{ Car } ;
ROLE: Cbr <{ Car Cxr } ;
TUPLE: Cb <{ Cbr } ;
ROLE: Ccr <{ Cbr } ;
TUPLE: Cc <{ Ccr } ;

GENERIC: m1 ( a -- b )
M: Car m1 drop "m1a" ;
M: Cxr m1 drop "m1x" ;

[ "m1a" ] [ Ca new m1 ] unit-test
[ "m1x" ] [ Cb new m1 ] unit-test
[ "m1x" ] [ Cc new m1 ] unit-test
: f1a ( -- o ) Ca new m1 ;
: f1b ( -- o ) Cb new m1 ;
: f1c ( -- o ) Cc new m1 ;
[ "m1a" ] [ f1a ] unit-test
[ "m1x" ] [ f1b ] unit-test
[ "m1x" ] [ f1c ] unit-test