C++ Unicode Problems/Questions

Question

I wrote two versions of a little program in C++ with MSVC on Windows 11:

First one:

#include <iostream>
#include <Windows.h>
int main()
{
 SetConsoleOutputCP(CP_UTF8);
 std::cout << u8"ä ü ö \n";
}

That did not work. But the following one did work:

#include <iostream>
#include <Windows.h>
int main()
{
 SetConsoleOutputCP(CP_UTF8);
 std::cout << "ä ü ö \n";
}

The difference was the u8 in front of the string literal.

Why did it not work? With "did not work" I mean, that the output on the console was not "ä ü ö" but other symbols.

• grek40: Please describe what actually happened in the first case. "did not work" could mean anything from doing nothing to blasting away half the universe.
• Ted Lyngmo: Do you mean that it actually compiled std::cout << u8"ä ü ö \n";? That's surprising. Must be an MSVC extension.
• Igor Tandetnik: Print numerical values of individual octets of the two string literals. This should prove illuminating.
• Remy Lebeau: @Tim what charset is the .cpp file itself saved as? If you do not specify /utf-8 during compiling then DO NOT save the file as UTF-8. But if your file IS saved as UTF-8 then you need /utf-8. Read up about your compiler's Source Charset and Execution Charset options. They affect how char strings are interpreted at compile-time and run-time, respectively. Also, your /D defines for Unicode only affect TCHAR-based strings+macros, none of which you are using in your example.
• Ted Lyngmo: @JohnBollinger I was thinking of the std::ostream& operator<<(std::ostream&, const char8_t*) overload required. It's been deleted since C++20 but I see that OP mentions using C++14 in the comments, so that clears that up. :-)