The law of hashes , the law of dictionary , states, keys are words, keys are strings, keys cannot be reference, hashes or arrays, keys are only strings, they're key words, like in a dictionary, a hash is a dictionary

so you cannot write my %hash = ( \%foo => \%bar ) as \%foo becomes a string ...

so whatever you had in mind for $values, you need to type up a different example of what you want, an example that is more sensible:)

unless you really wanted the stringification of \%foo as an actual key (I doubt that)