Does this really do what the poster wants? My impression was that Data::Alias is designed more to handle magic aliasing of scalars (possibly references), such as occurs in fors and subroutines, than to handle non-scalars such as subroutines. Of course, you can use

alias *old_func = \&new_func,
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but I don't see what that gains over just

*old_func = \&new_func.
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I searched the Data::Alias documentation for 'code' and 'function', but couldn't find anything indicating what I might be missing.