[Bug libstdc++/119197] [feat req] `std::expected` should be nodiscard

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119197

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |16.0
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Fixed for GCC 16