Francois Gouget wrote:
On Fri, 18 Jan 2002, Andriy Palamarchuk wrote:
Using macro name "UNICODE" instead of "_UNICODE"
is a
typo, right?
No, not necessarily. Windows has both and
dinput.h,
for instance, uses UNICODE, not _UNICODE.
But I have no idea why they have two.
I did a little research and found in a few places information that UNICODE is used by Windows headers, _UNICODE is used by C-runtime/MFC headers. However I did not find official explanation of this. Some examples, including a few MSDN ones, define both. E.g. see: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wss/wss/_ex...
Can you tell now where we need to use which one? Andriy Palamarchuk
__________________________________________________ Do You Yahoo!? Send FREE video emails in Yahoo! Mail! http://promo.yahoo.com/videomail/
On Mon, 21 Jan 2002, Andriy Palamarchuk wrote:
Francois Gouget wrote:
On Fri, 18 Jan 2002, Andriy Palamarchuk wrote:
Using macro name "UNICODE" instead of "_UNICODE"
is a
typo, right?
No, not necessarily. Windows has both and
dinput.h,
for instance, uses UNICODE, not _UNICODE.
But I have no idea why they have two.
I did a little research and found in a few places information that UNICODE is used by Windows headers, _UNICODE is used by C-runtime/MFC headers. However I did not find official explanation of this. Some examples, including a few MSDN ones, define both. E.g. see: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wss/wss/_ex...
Can you tell now where we need to use which one?
All Windows headers use UNICODE except the following which also make references to _UNICODE:
* msacm.h This one does something like: #if defined(UNICODE) && !defined(_UNICODE) #define _UNICODE #endif
* edk.h This one defines _UNICODE if UNICODE is defined, but then it will only test UNICODE!
* oledlg.h This one will make sure that if one of UNICODE or _UNICODE is defined, then the other one is defined too.
* bdnapi.h, dbdao.h, tchar.h These only test _UNICODE
* sqlole.h This one tests both and defines SQLOLE_UNICODE to simplify further tests.
It's a big mess if you ask me. The reason why there is no official explanation is that there was simply no design. But currently our headers all do the right thing (tchar.h uses _UNICODE and msacm.h uses neither for now).
The Petzold mentions that you need _UNICODE for tchar.h and UNICODE for the other headers but does not go into why this was done this way. All it says is to define both if you are writing a Unicode application.
-- Francois Gouget fgouget@free.fr http://fgouget.free.fr/ "Utilisateur" (nom commun) : Mot utilisé par les informaticiens en lieu et place d'"idiot".
-
Andriy Palamarchuk -
Francois Gouget