Don't forget to use B::Deparse to gain insight

C:\>perl -MO=Deparse -e" @foobar = foo() || warn 'Yikes!'"
@foobar = foo() || warn('Yikes!');
-e syntax OK

C:\>perl -MO=Deparse -e" @foobar = foo() or warn 'Yikes!'"
warn 'Yikes!' unless @foobar = foo();
-e syntax OK

C:\>
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