# Doesn't work
sort \&numeric @list;

# Works
my $sorter = \&numeric; 
sort $sorter @list;

##</code><code>##

sub sort_hashkey($$) {
    my ($a,$b) = @_;
    $a->{foo} <=> $b->{foo};
}

my @sorted = sort_hashkey @list;

##</code><code>##

my $sorter = sorthash_numeric('foo');
my @sorted = sort $sorter @list;

##</code><code>##

my @sorted = sort sorthash_alpha('foo') @list;