+ check { my ($k, $v) = each %h } { copy => 1 }, 'tied hash each';
+
+ my @k = check { keys %h } { }, 'tied hash keys';
+ is_deeply [ sort @k ], [ qw/a c/ ], 'copy: tied hash keys correctly';
+
+ my @v = check { values %h } { copy => 2 }, 'tied hash values';
+ is_deeply [ sort { $a <=> $b } @v ], [ 1, 3 ], 'copy: tied hash values correctly';
+
+ check { undef %h } { }, 'tied hash undef';
+}