[Bug libstdc++/79511] Convertation issues in std::codecvt_utf8_utf16

[mikhail at pilin dot name]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79511

--- Comment #7 from ww898 <mikhail at pilin dot name> ---
Yes, I have: https://github.com/ww898/utf-cpp.

To make errors please uncomment here:
https://github.com/ww898/utf-cpp/blob/master/test/utf_converters_test.cpp#L781

P.S. It is possible to use no library version of boost test, but it requires
some changes in test sources and CMake.