You may find the replies to confusion about blessing inside a constructor interesting.

Bottom line: $class = ref($proto) || $proto; treats new as both a constructor and as a cloner. Better to have a separate clone method if you need one and simply:

sub new {
    my ($class, %options) = @_;

    # validate options
    return bless \%options, $class;
}
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which makes new a class method called by:

my $obj = Bob::MyObject->new (option => 1, );
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but not as:

my $newObj = $obj->new (option => 1, );
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