sub foo { print caller(0); }
my $cref = sub { return 1; };

my $h = {
    a => 1,
    b => foo(),
    d => 'foo',
    c => $cref,
    m => 'bar',
};

##</code><code>##

sub foo { print caller(0); }

my $h = {
    a => 1,
    c => sub { return 1; },
    b => foo(),
    d => 'foo',
    m => 'bar',
};