Why does Perl think I'm trying to use a variable $typ:: when I can't ever declare $typ:: anyways?

You can't declare $1 or $Module::foo either, so that's a bad criteria for defining what's a variable.

%typ:: is a valid variable (the symbol table for package typ), so the name typ:: is necessarily valid.

$ perl -le'$typ="abc"; $dat="def"; $typ::="123"; print "$typ::$dat"'
123def
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Workarounds:

$ perl -le'$typ="abc"; $dat="def"; $typ::="123"; print "${typ}::$dat"'
abc::def
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$ perl -le'$typ="abc"; $dat="def"; $typ::="123"; print "$typ\::$dat"'
abc::def
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$ perl -le'$typ="abc"; $dat="def"; $typ::="123"; print $typ."::".$dat'
abc::def
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