C ++ UNICODE和STL

Question

The Windows API seems big on UNICODE , you make a new project in Visual C++ and it sets it to UNICODE by default.
And me trying to be a good Windows programmer, I want to use UNICODE .

The problem is the C++ Standard Library and STL (such as std::string , or std::runtime_error ) don't work well with UNICODE strings. I can only pass a std::string , or a char* to std::runtime_error , and i'm pretty sure std::string doesn't support UNICODE .

So my question is, how should I use things such as std::runtime_error ? Should I mix UNICODE and regular ANSI ? (I think this is a bad idea...)
Just use ANSI in my whole project? (prefer not..) Or what?

Answer 1

In general you shouldn't mix those two encodings. However, exception messages are something that is only of interest to the developer (eg in log files) and should never be shown to the user (but look at Jim's comment for an important caveat).

So you are on the safe side if you use UNICODE for your whole user-faced interface and still use std::exception etc. behind the scenes for developer messages. There should be no need ever to convert between the two.

Furthermore, it's a good trick to define a typedef for UNICODE -independent strings in C++:

typedef std::basic_string<TCHAR> tstring;

… and analogously define tcout , tcin etc. conditionally:

#ifdef UNICODE
    std::wostream& tcout = std::wcout;
    std::wostream& tcerr = std::wcerr;
    std::wostream& tclog = std::wclog;
    std::wistream& tcin = std::wcin;
#else
    std::ostream& tcout = std::cout;
    std::ostream& tcerr = std::cerr;
    std::ostream& tclog = std::clog;
    std::istream& tcin = std::cin;
#endif

Answer 2

Josh,

Please have a look at my answer here: https://softwareengineering.stackexchange.com/questions/102205/should-utf-16-be-considered-harmful

There is growing number of engineers who believe std::string is just perfect for unicode on Windows, and is the right way to write portable and unicode-correct programs faster.

Answer 3

Take a look at this (rather old now) article on CodeProject: Upgrading an STL-based application to use Unicode . It covers the issues you're likely to hit if you're using the STL extensively. It shouldn't be that bad and, generally speaking, it's worth your while to use wide strings.

Answer 4

要使用Windows Unicode API，只需使用宽字符串版本 - wstring等。它对exception::what()没有帮助，但为此你可以使用UTF-8编码，如果你真的需要Unicode。