Typeglobs

Assigning a reference to a typeglob makes the two names really point to the same value:

    *duck = \$foo; # $duck is now 4
    $duck += 4; # $foo and $duck are 8

You can assign any type of reference to a typeglob:

    *git_r_done = \&doit;
    git_r_done(); # "done"

The parens (or a sigil) are needed for function calls since the function was never really defined.