$ perl -Mstrict -cwe '*foo->()'
    Name "main::foo" used only once: possible typo at -e line 1.
    -e syntax OK

    $ perl -Mstrict -we '*foo->()'
    Name "main::foo" used only once: possible typo at -e line 1.
    Undefined subroutine &main::foo called at -e line 1.