You don't actually need the first 1; line there, before the package Bar; statement, though it's harmless. And number 1 is apperantly special as it doesn't generate useless constant in void warning, as other constants.

$ perl -c -we '1'
-e syntax OK
$ perl -c -we '3'
Useless use of a constant in void context at -e line 1.
-e syntax OK
$ perl -c -we '"OK"'
Useless use of a constant in void context at -e line 1.
-e syntax OK
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I frankly wondered at first, but, fortunately diagnostics has the fact:

This warning will not be issued for numerical constants equal to 0 or 1 since they are often used in statements like

   1 while sub_with_side_effects();
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String constants that would normally evaluate to 0 or 1 are warned about.

One more thing, if you really need Foo from Bar, you might consider to use @ISA for inheritance or Exporter for importing Foo's symbols.