[Voted into the WP at the March, 2009 meeting.]

Proposed resolution (March, 2008):

Add the indicated sentence to the end of 9.7.1 [dcl.enum] paragraph 5:

...It is possible to define an enumeration that has values not defined by any of its enumerators. If the enumerator-list is empty, the values of the enumeration are as if the enumeration had a single enumerator with value 0.

According to 9.7.1 [dcl.enum] paragraph 6, the underlying type of an enumeration with an empty enumeration-list is determined as if the enumeration-list contained a single enumerator with value 0. Paragraph 7, which specifies the values of an enumeration and the minimum size of bit-field needed represent those values needs a similar provision for empty enumeration-lists.