Erm, Scalar::Util::readonly reports but doesn't set the readonly flag: 

       readonly SCALAR
           Returns true if SCALAR is readonly.

               sub foo { readonly($_[0]) }

               $readonly = foo($bar);              # false
               $readonly = foo(0);                 # true

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In reply to Re^2: Constant string reference by Fletch
in thread Constant string reference by przemo

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