If you have a bunch of hashes (could also be a bunch of arrays) that you need to define en masse and identically initialize as non-empty, something like this works:

>perl -wMstrict -MData::Dump -le
"use constant HASH => qw(foo bar  1 one);
 ;;
 %$_ = HASH for \my (%hash1, %hash2);
 dd \%hash1;
 dd \%hash2;
"
{ 1 => "one", foo => "bar" }

{ 1 => "one", foo => "bar" }
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