Full name of submitter: Evan Girardin (he gave me permission to file this issue on his behalf)

Reference (section label): [over.ics.rank], [over.ics.ref]

Issue description: The tiebreaker rules in [over.ics.rank]/4 should apply to the case where one conversion has a reference as its destination type and the other does not. All known implementations agree. Therefore, [over.ics.ref] should be updated to specify the source and destination types for a derived-to-base reference binding.

Suggested resolution: Edit [over.ics.ref]/1:

When a parameter of type "reference to cv T" binds directly ([dcl.init.ref]) to an argument expression:

• If the argument expression has a type that is a derived class of the parameter type, the implicit conversion sequence is a derived-to-base conversion from the class of the parameter type to T ([over.best.ics]).
• Otherwise, if the type of the argument is possibly cv-qualified T, or if T is an array type of unknown bound with element type U and the argument has an array type of known bound whose element type is possibly cv-qualified U, the implicit conversion sequence is the identity conversion.
• Otherwise, if T is a function type, the implicit conversion sequence is a function pointer conversion.
• Otherwise, the implicit conversion sequence is a qualification conversion.

Strike subbullets 2 and 6 from [over.ics.rank]/4.5.

If class B is derived directly or indirectly from class A and class C is derived directly or indirectly from B,

• conversion of C* to B* is better than conversion of C* to A*, [Example: ...]
• binding of an expression of type C to a reference to type B is better than binding an expression of type C to a reference to type A,
• conversion of A​::​* to B​::​* is better than conversion of A​::​* to C​::​*,
• conversion of C to B is better than conversion of C to A,
• conversion of B* to A* is better than conversion of C* to A*,
• binding of an expression of type B to a reference to type A is better than binding an expression of type C to a reference to type A,
• conversion of B​::​* to C​::​* is better than conversion of A​::​* to C​::​*, and
• conversion of B to A is better than conversion of C to A.

[Note: ...]