Adds example addresses https://www.nntp.perl.org/group/perl.perl6.use…

…rs/2018/06/msg5056.html

doc/Language/objects.pod6

@@ -987,11 +987,13 @@ anonymous roles are supported.
     my $i = 2 but R;
     sub f(\bound){ put bound };
     f($i); # OUTPUT: «hidden!␤»
+    my @positional := <a b> but R;
+    say @positional.^name; # OUTPUT: «List+{R}␤»
 
 Note that the object got the role mixed in, not the object's class or the
 container. Thus, @-sigiled containers will require binding to make the role
-stick. Some operators will return a new value, which effectively strips
-the mixin from the result.
+stick as is shown in the example with C<@positional>. Some operators will return
+a new value, which effectively strips the mixin from the result.
 
 The operator infix:<but> is narrower than the list constructor. When providing
 a list of roles to mix in, always use parentheses.