As the require manpage mentions, if you put a coderef in @INC, it will get processed every time a module gets 'used' or 'required'.

CPAN modules that use this technique

• everywhere
• ifdef
• PAR
• deferred
• only-latest
• Devel::FIXME
• Devel::TraceINC
• Devel::SearchINC
• these modules don't do much complex stuff, but maybe they're still useful examples
  • Net::Curl::Compat
  • Class::HPLOO
  • App::FatPacker

Discussions of this technique

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