proper style for interfacing with legacy TCHAR code

Question

I'm modifying someone else's code which uses TCHAR extensively. Is it better form to just use std::wstring in my code? wstring should be equivalent to TString on widechar platforms so I don't see an issue. The rationale being, its easier to use a raw wstring than to support TCHAR... e.g., using boost:wformat.

Which style will be more clear to the next maintainer? I wasted several hours myself trying to understand string intricacies, it seems just using wstring would cut off half of the stuff you need to understand.

typedef std::basic_string<TCHAR> TString; //on winxp, TCHAR resolves to wchar_t
typedef basic_string<wchar_t, char_traits<wchar_t>, allocator<wchar_t> > wstring;

...the only difference is the allocator.

In the unlikely case that your program lands on a Window 9x machine, there's still an API layer that can translate your UTF-16 strings to 8-bit chars. There's no point left in using TCHAR for new code development. source

Answer 1

If you are only intending on targetting Unicode (wchar_t) platforms, you are better off using std::wstring. If you want to support multibyte and Unicode builds, you will need to use TString and similar.

Also note that basic_string defaults the char_traits and allocator to one based on the passed in character type, so on builds where UNICODE (or _UNICODE, I can never remember which), TString and wstring will be the same.

NOTE: If you are just passing the arguments to various APIs and not doing any manipulations on them, you are better off using const wchar_t * instead of std::wstring directly (especially if mixing Win32, COM and standard C++ code) as you will end up doing less conversions and copying.

Answer 2

TCHAR used to be more important when you where going to compile the binaries twice, once for char and a second for wchar_t.

You can still make this choice if you like, changing the MSVC project settings from MBCS to Unicode and back.

This also means when calling the windows API you will have the matching data type.