#!/usr/bin/env perl
use warnings;
use 5.020;
use feature 'postderef';
no warnings 'experimental::postderef';

my %hoh = ( foo=>{a=>1,b=>2}, bar=>{c=>3,d=>4} );

for my $name (keys %hoh) {
	while ( my ($key,$value) = each $hoh{$name}->%* ) {
		say "$key: $value";
	}
}