Basic Unicode character/string support absent even in modern C++

[Piotr Karocki]

>> Or better C++ compiler, which understand Unicode source files.
> My latest GCC and Clang don't have any problem with the source files.
> The limitation is with the standard libraries which don't provide the
> required functionality.

 But you wrote that you got messages from compiler not from runtime. And
error from compiler is irrelevant to any error in any libraries, standard or
not, as code is not executed yet.