To expand a bit:

The value of a hashref depends on the context - and not only scalar vs list, but it's different between numeric and string context, e.g.

perl -e 'print {}'   # string-context
HASH(0x114dcb8)

perl -e 'print 0 + {}'  # numeric context
18996408

perl -e '{} + 0'    # does not compile
syntax error at -e line 1, near "} +"
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