I have a bit of a problem. I want to know if an argument to a sub is a variable or a constant, that is, is it an lvalue or not?

Let's say I call a function called foo thusly... 

  foo($a, "b");

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Inside foo(), I'd like to be able to determine that $_[0] is a variable (and thus an lvalue) and that $_[1] is a constant (and thus not an lvalue). Any ideas on how?

In reply to How do you tell if a sub argument is an lvalue? by rsmah

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