Renaming of enumeration constant

["Xenos" <dont.spam.me@spamhate.com>]

Just a curiosity question:

What is the difference (advantages, etc.) of defining a function rename for
an enumeration constant over just creating a constant.  Consider:

package X is
  type E is (A, B, C);
end X;

with X;
package Y is
   function A return X.E renames X.A;
end Y;

with X;
package Z is
  A : constant X.E := X.A;
end Z;

Is the "A" in Y treated any different than the "A" in Z by the compiler, or
will both achieve the same results.  Is one considered "better" (whatever
that means) than the other?

Thanks,

DrX