https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114477
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- The notes say it was closed because you didn't want to work on it. https://github.com/cplusplus/papers/issues/1726#issuecomment-2014094319 It sounds like the Ranges study group supported the direction. If you want to pursue it, just submit a revised paper. I think it would be sufficient to expand the discussion of the libstdc++ implementation to point out that it can't break GCC users because those constructors don't exist anyway. The MSVC implementation should be inspected, and advice from MSVC STL maintainers sought, to determine the impact on their users. Does range-v3 provide those constructors? What about other third-party ranges libraries?