First, perldoc perlref is your friend!
Have a look and your life will be much better.
In your example, the structure $scalar->{} will autovivify (*) an anonymous HASH reference, just as:
my $hash_ref = {}; ${$hash_ref}{foo} = "bar";
(*) More about autovivification: http://tlc.perlarchive.com/articles/perl/ug0002.shtml
Updated: Fixed typos =/
In reply to Re: Building Hashrefs
by deibyz
in thread Building Hashrefs
by Anonymous Monk
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