I need a function which takes two hash references as an input and outputs a hash reference, which has all the keys that are unique to one of the inputs and in the case of common keys the value belonging to the second one overwrites the first one. Of course I could iterate over the keys, but in the case of nested structures this has to be recursive. The whole thing gets very complicated and presumably slow. Is there an optimized solution to this problem? 
my $ref1=
    {
    
        ref1_specific_key => 'some value',
        
        common_key =>
        {
            
            ref1_specific_subkey => 'some sub value',
        
            common_subkey => 'foo'
        }
        
    };
    
my $ref2=
    {
    
        ref2_specific_key => 'some other value',
    
        common_key =>
        {
            ref2_specific_subkey => 'some other sub value',
            
            common_subkey => 'bar'
        }
        
    };
    
my $output=
    {
    
        ref1_specific_key => 'some value',
        
        ref2_specific_key => 'some other value',
    
        common_key =>
        {
        
            ref1_specific_subkey => 'some sub value',
            
            ref2_specific_subkey => 'some other sub value',
        
            common_subkey => 'bar'
        }
        
    };

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In reply to What is the easiest way to merge two hashes? by tkguifan

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