This works now: $ perl6-m -e 'my @a = 1..10; @a.first(* %% 2).++; say @a' 1 3 3 4 5 6 7 8 9 10
I added a test for this (and for the example with grep) to S32-list/first.t and S32-list/grep.t, respectively, with the following commit: https://github.com/perl6/roast/commit/4295bfcfae
