This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 118e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2025-11-05

896. Rvalue references and rvalue-reference conversion functions

[Voted into WP at October, 2009 meeting.]

Consider the following example:

 struct A { } a; struct B { operator A&&() { return static_cast<A&&>(a); } }; A&& r = B(); 

One would expect that r would be bound to the object returned by B::operator A&&(), i.e., a. However, the logic in 9.5.4 [dcl.init.ref] paragraph 5 requires that the result of the conversion function be copied to a temporary and r bound to the temporary.

Probably the way to address this is to add another top-level bullet between the first and second that would essentially mimic the first bullet except dealing with rvalue references: direct binding to reference-compatible rvalues or to the reference-compatible result of a conversion function. (Note that this should only apply to class rvalues; the creation of a temporary for non-class rvalues is necessary to have an object for the reference to bind to.)

(See also issue 656.)

Proposed resolution (September, 2009):

This issue is resolved by the resolution of issue 656.