use strict;
use warnings;

my $aref = [qw(1 2 3 4)];

if ( eval { %$aref; 1 } ) {
  print "aref is a href\n";
  my %hash = %$aref;
}

##</code><code>##

if ( eval { my $foo = %$aref; 1 } ) {
  print "aref is a href\n";
  my %hash = %$aref;
}

##</code><code>##

Pseudo-hashes are deprecated 

##</code><code>##

sub isa_hash {
  no warnings 'void';
  my $hsh = shift();
  return if eval { @$hsh; 1 };
  return 1 if eval { %$hsh; 1 };
  return;
}

sub isa_array {
  no warnings 'void';
  my $arr = shift();
  return 1 if eval { @$arr; 1 };
  return;
}

##</code><code>##

if ( eval { 1 + %$possible_href } ) {
    return 1;
}