[Bug c++/38172] warn_unused_result does not work with structs not containing a copy constructor

[gcc at bobbyperu dot info]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38172

--- Comment #13 from Sergio Martins <gcc at bobbyperu dot info> ---
Any point in using warn_unused_result instead of nodiscard on compilers that
support both ?

Probably a good time to close this bug. While it would be nice to have it fixed
there's no point on wasting resources on it anymore.