Proposed resolution (approved by CWG 2024-08-16):

Change in 12.2.2.7 [over.match.ref] bullet 1.1 as follows:

Let R be a set of types including

• “lvalue reference to cv2 T2” (when initializing converting to an lvalue reference or an rvalue reference to function) and
• “cv2 T2” and “rvalue reference to cv2 T2” (when initializing converting to an rvalue reference or an lvalue reference to of function type)

for any T2.

There is implementation divergence handling the following example:

  struct A {
    A(const A&) = delete;
  };
  struct B {
    operator A&&();
  };
  const A& r = B();

Conversion to an lvalue pursuant to 9.4.4 [dcl.init.ref] bullet 5.1 fails due to the attempt to invoke a deleted function, but conversion to an rvalue according to 9.4.4 [dcl.init.ref] bullet 5.3 would succeed, except that 12.2.2.7 [over.match.ref] bullet 1.1 hinges on the target type of the initialization, not the target type of the conversion.