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Re^3: Copy a builtin sub to a different name and then override

by Haarg (Curate)
on Jun 03, 2018 at 10:27 UTC ( #1215774=note: print w/replies, xml ) Need Help??


in reply to Re^2: Copy a builtin sub to a different name and then override
in thread Copy a builtin sub to a different name and then override

This isn't checking if CORE::GLOBAL::sleep exists, it's forcing it to exist. It's another form of autovivification. Taking a reference to a nonexistent sub like this will create a stub in its place (like sub CORE::GLOBAL::sleep;). A stub of course isn't callable.

The correct way to check for the existence of a sub is using either exists &Some::sub or defined &Some::sub. exists will return true for subs that exist, even if they are stubs. defined will return true only for not-stub subs.

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