This duplicates common keys.

Interestingly, with the postdereference, we can use a hash slice in an assigment: 

my %A = (a => 1, b => 2, D => 3);
my %Z = (z => 9, y => 8, D => 7);
(\ my %all_keys)->@{keys %A, keys %Z} = ();
say for keys %all_keys;

[download]

The same construct using the "old" dereference doesn't work: 

@{ \ my %all_keys }{keys %A, keys %Z} = ();
say for keys %all_keys;  # Global symbol "%all_keys" requires explicit
+ package name (did you forget to declare "my %all_keys"?)

[download]
because, alas, the my is scoped inside the dereference block.

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

In reply to Re^2: Problem combining hashes by choroba
in thread Problem combining hashes by jh

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