R
R.Kaiser
Where can I find which Unicode characters are valid for identifiers in
Visual C++ 2005?
Thanks
Richard
Visual C++ 2005?
Thanks
Richard
C
Carl Daniel [VC++ MVP]
R.Kaiser said:
According to the VC++ documentation:
http://msdn2.microsoft.com/en-us/library/565w213d.aspx
The following characters are valid as the first character of a name:
_ a b c d e f g h i j k l m
n o p q r s t u v w x y z
A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
And the following characters, in addition to the above, are valid as the
second or subsequent character:
0 1 2 3 4 5 6 7 8 9
Plus, the $ character is also valid as a MS extension.
-cd
V
Vladimir Nesterovsky
More accurate definition according to the spec is:
2.10 Identifiers [lex.name]
identifier:
nondigit
identifier nondigit
identifier digit
nondigit: one of
universal-character-name
_ a b c d e f g h i j k l m
n o p q r s t u v w x y z
A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
digit: one of
0 1 2 3 4 5 6 7 8 9
1 An identifier is an arbitrarily long sequence of letters and digits. Each
universal-character-name in an identifier shall designate a character whose
encoding in ISO 10646 falls into one of the ranges specified in Annex E.
Upper- and lower-case letters are different. All characters are significant.
2 In addition, some identifiers are reserved for use by C++ implementations
and standard libraries (17.4.3.1.2) and shall not be used otherwise; no
diagnostic is required.
This means that national characters can be a part of a name. I've tested
Russian and Hebrew characters. It's worked.
R
R.Kaiser
Thanks Carl and Vladimir, what you are listing are the valid characters
for Standard C++ identifiers.
But in Windows Forms Applications, Visual C++ 2005 also accepts
extensions, like German Umlauts in ordinary identifiers
int Zähler;
or names like
àÀáÁãÃçÇéÉêÊÍíóÓúÚüÜ
for names of Windows controls. I could use this expression as a value
for the Name property of e.g. a Button by setting it in the Properties
window.
The rules seem to be quite complicated:
int Zähler; // valid
int Z$hler; // valid
int Zä$hler; // error
int xàÀáÁãÃçÇéÉêÊÍíóÓúÚüÜ; // valid
int àÀáÁãÃçÇéÉêÊÍíóÓúÚüÜ; // error
Despite intensive search, I could find no reference for the valid
characters of identifiers in VS2005. I would expect, that certain Arabic
and Asian characters are also valid.
Richard Kaiser
for Standard C++ identifiers.
But in Windows Forms Applications, Visual C++ 2005 also accepts
extensions, like German Umlauts in ordinary identifiers
int Zähler;
or names like
àÀáÁãÃçÇéÉêÊÍíóÓúÚüÜ
for names of Windows controls. I could use this expression as a value
for the Name property of e.g. a Button by setting it in the Properties
window.
The rules seem to be quite complicated:
int Zähler; // valid
int Z$hler; // valid
int Zä$hler; // error
int xàÀáÁãÃçÇéÉêÊÍíóÓúÚüÜ; // valid
int àÀáÁãÃçÇéÉêÊÍíóÓúÚüÜ; // error
Despite intensive search, I could find no reference for the valid
characters of identifiers in VS2005. I would expect, that certain Arabic
and Asian characters are also valid.
Richard Kaiser
G
Guest
Vladimir Nesterovsky said:
How do you save the file? as utf-8 or utf-16, with unicode marker ?
--PA
C
Carl Daniel [VC++ MVP]
Vladimir Nesterovsky said:
Yes, I know what the C++ standard says - I was simply quoting what the VC++
2005 documentation says. I rather suspected that the documentation was
wrong, since I know there was a bunch of work done in the 7.0 compiler to
support unicode source files.
Good to know, thanks.
-cd
C
Carl Daniel [VC++ MVP]
R.Kaiser said:
Those are also valid according to the C++ standard, and apparently according
to VC++ (but not according to the VC++ documentation - go figure).
The cases you cite that don't work are interesting. What source file
encoding were you using? I can imagine that if the source file was, for
example, Latin-8 but the compiler concluded (incorrectly) that it was UTF-8,
that certain pairs of characters would end up being illegal.
I would expect that only a Unicode encoding would be safe for files with
non-ASCII characters, but I haven't done any experimenting in that area
myself.
-cd
R
R.Kaiser
Thanks Vladimir,
I have overlooked the reference to Annex E in the standard.
Richard
I have overlooked the reference to Annex E in the standard.
Richard
Vladimir said:
R
R.Kaiser
Carl said:
I used
Western European (Windows) - Codepage 1252
Richard
I can imagine that if the source file was, for
M
Mihai N.
I would expect that only a Unicode encoding would be safe for files with
If you want something else, you will be (of course) limited to characters
from that code page.
And you can inform the compiler what that is by using #pragma setlocale
(http://msdn2.microsoft.com/en-us/library/3e22ty2t.aspx)
When in doubt, go Unicode
If you want something else, you will be (of course) limited to characters
from that code page.
And you can inform the compiler what that is by using #pragma setlocale
(http://msdn2.microsoft.com/en-us/library/3e22ty2t.aspx)