On Fri, Jun 8, 2012 at 1:40 PM, Johan Tibell <johan.tibell at gmail.com> wrote: > GHC used to complain when you use UNPACK with something that can't be > unpacked, but that warning seems to have been (accidentally) removed > in 7.4.1. Turns out the warning is only on if you compile with -O or higher. -- Johan