[Bug libstdc++/80187] C++ variant should be trivially copy constructible if possible

[ambrop7 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80187

--- Comment #3 from Ambroz Bizjak <ambrop7 at gmail dot com> ---
Hey,
Does this idea help: https://godbolt.org/g/3Iqp2c ?
The storage is an array of "special" byte classes which have empty
constructors/assign when those would be implemented by one of the mixins.