I don't know of a way to do that. But perhaps you'd find the following solution acceptable: writing your own wrapper functions to which you can refer. 

my %op = (
  'toupper' => sub { uc shift },
  ...
);

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In reply to Re: How do I get a reference to a builtin function? by dws
in thread How do I get a reference to a builtin function? by adram

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