Here you go: default variable to pass string argument to many built-in functions and operators, which typically return their result in the same variable. Yes,

Here you go: default variable to pass string argument to many built-in functions and operators, which typically return their result in the same variable. Yes, it took a little longer. No, it didn't took that much longer to leave out plainly invalid and misleading description. No, I didn't need to put corner cases there, exactly the same way as you wouldn't specify corner cases for Yacc to describe what it does.