>perl -E"1 for @h{x}; say exists($h{x}) || 0;
1

>perl -E"sub {}->( @h{x} ); say exists($h{x}) || 0;
1

>perl -E"my $r = \@h{x}; say exists($h{x}) || 0;
1

##</code><code>##

>perl -E"1 for $h{x}; say exists($h{x}) || 0;
1

>perl -E"sub {}->( $h{x} ); say exists($h{x}) || 0;
0

>perl -E"\@h{x}; say exists($h{x}) || 0;
1

##</code><code>##

>perl -E"sub {}->( @{[ @h{x} ]} );  say exists($h{x}) || 0;"
0

>perl -E"sub {}->( do { @h{x} } );  say exists($h{x}) || 0;"
0