Proposed resolution (March, 2011):

This issue is resolved by the resolution of issue 692 in document N3281.

The specification for how to handle default arguments and ellipsis in partial ordering of function templates is confusing. 13.7.7.3 [temp.func.order] paragraph 5 currently reads,

The presence of unused ellipsis and default arguments has no effect on the partial ordering of function templates.

It is not clear what “unused” means in this context. According to the original issue resolution that resulted in this wording (N1053, item 6.55), the intent was that “When partial ordering of function templates containing a different number of parameters is done, only the common parameters are considered.” Presumably this would include parameters with default arguments if each function had such parameters in corresponding positions.

The wording needs to be revised to make this intent clear.