[Bug libstdc++/80451] [6/7 Regression] return implicit type conversion to std::experimental::optional does not compile

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80451

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-04-18
            Summary|return implicit type        |[6/7 Regression] return
                   |conversion to               |implicit type conversion to
                   |std::experimental::optional |std::experimental::optional
                   |does not compile            |does not compile
     Ever confirmed|0                           |1

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This isn't a bug in optional, it's a bug in the implementation of Core 1579 in
r212099 (so my fault). Reported as PR 80452.

The implementation of experimental::optional in GCC 5 didn't rely on converting
moves, so wasn't affected by this bug. We might need a workaround in optional
until the compiler is fixed.