$ diff -u \
   <( perl -Mstrict -Mwarnings -MO=Concise -e'my ($u, $v)    = split /,/, "U,V";' 2>&1 ) \
   <( perl -Mstrict -Mwarnings -MO=Concise -e'(my $u, my $v) = split /,/, "U,V";' 2>&1 ) \
&& echo same
same