Placing entries at the end of @INC means that modules if found in the original @INC take precendence and are loaded instead of the ones you want loading. The chances are of such a case are slim but entirely possible especially if the user isn't aware of the perl module namespace.

I'm not sure why you are advocating adding to the back of @INC or how it relates to the thread, but adding to the front of @INC is definitely the way to go.

There are two reasons to add to @INC:

• To have require locate a module that wouldn't get located otherwise. In this case, it doesn't matter if you add to the front or back of @INC since there's only one copy of the module.

• To have require locate the prefered version of a newer module when require would have locate another version of the module otherwise. In this case, you need to add to the front of @INC.

So placing it at the front is claearly preferable. There are no reasons to place it at the back.

what if non-standard versions of ../strict.pm or ../warnings.pm existed?

You're inventing problems. If .. was added to the end of @INC, your non-standard strict.pm would never get loaded, so why did you write it?

---

Now back on topic,

eval "use Foo::Bar 5.01 qw| raz baz taz |";  # try loading v5.01
if ($@) {                  # if loading v5.01 failed
   warn "$@";              # fallback to using standard (v5.00)
   use Foo::Bar qw| baz |; # raz and taz arent valid tags here
}
[download]

You still haven't addressed the problem I mentioned (and fixed) in my previous post. The second use will get executed first, and unconditionally. Since both use load the same module, all you'll get is a Subroutine baz redefined warning. However, it's skirting with danger.

Furthermore, it doesn't really make sense to import raz and taz from 5.01 if you don't create replacements when loading from <5.01.

BEGIN {
   require Foo::Bar;

   eval { Foo::Bar->VERSION(5.01) };
   if ($@) {
      warn("Warning: Foo::Bar not desired version 5.01. " .
           "Proceeding anyway\n");

      import Foo::Bar qw( baz );
      *raz = sub { ... };
      *taz = sub { ... };
   } else {
      import Foo::Bar qw( raz baz taz );
   }
}
[download]

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