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I'm working on a project on C++ of numeric calculus. I need to incorporate to a complete project that is written on ansi C ... Naturally, after compilation, the C functions are presenting big errors.
Is it possible to incorporate, in any way, to my C++ project, other projects written on ansi C?
Thanks in advance !
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Yes, and it is very easy. The VC++ headers have this in many of the files. Just add this little section :
#ifdef __cplusplus
extern "C" {
#endif
// your C prototypes go here
#ifdef __cplusplus
}
#endif
The Ten Commandments For C Programmers
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I'm trying to make a map like this:
CMap<cstring,cstring&,buddyinfo,buddyinfo&> *BuddyList;
with BuddyInfo being a struct. But, I get this error when I try compiling:
error C2440: 'type cast' : cannot convert from 'CString' to 'DWORD_PTR'
The error is in the second-to-last line in the following code from afxtempl.h:
template<class arg_key="">
AFX_INLINE UINT AFXAPI HashKey(ARG_KEY key)
{
// default identity hash - works for most primitive values
return (DWORD)(((DWORD_PTR)key)>>4);
}
What am I doing wrong? Thanks!
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IGx89 wrote:
What am I doing wrong? Thanks!
First, your template arguments are not visible because you typed < instead of <, which you can enter using the buttons below this window if you prefer.
Second, why are you using CMap instead of std::map ?
Apart from that, I cannot comment, because I use *real* containers, not the rubbish that comes with MFC. If you have some reason for using them, then I wish you luck in finding an answer, but making your template arguments visible may help people in replying.
Christian
Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002
During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002
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Christian Graus wrote:
because I use *real* containers
wow. i hope i never have to ask you a question, sir.
-c
bit, n:
A unit of measure applied to color. Twenty-four-bit color refers to expensive $3 color as opposed to the cheaper 25 cent, or two-bit, color that use to be available a few years ago.
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I know. CG has become an elitist.
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I don't know what you mean. My comment may have come across badly, but I only replied to explain the missing template parameters in the question, and I needed to explain that I couldn't help further, and wanted to recommend STL.
Christian
Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002
During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002
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Christian Graus wrote:
and I needed to explain that I couldn't help further, and wanted to recommend STL.
I agree that the STL is what any good programmer would use, but they way you responded to his post made you seem like you were looking down on him for not using the STL.
I would say that Templates should be understood before one can call themselves a C++ programmer, and i really don't get why so many people have problems with using templates. I use templates instead of function overloading, and for many of my classes as well...so I do agree with you 100%. 
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Christian Graus wrote:
Second, why are you using CMap instead of std::map ?
Apart from that, I cannot comment, because I use *real* containers, not the rubbish that comes with MFC. If you have some reason for using them
So you figure I should change all my MFC-based containers to std ones? Gah.. the churn!!! 
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No, I would not recommend that. It's a waste of time to change working code. But I'd strongly recommend you learning how they work and using them in future. Have you used STL before ? I imagined you hadn't if you were using MFC containers, which are really a pale imitation.
I have some articles here on STL if you don't have any experience with them.
Christian
Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002
During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002
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Well, we use something to STL similar at work (I think it's our own stuff based on STL), so i've exposed to it.
But..I tried using STL for something I was doing at home, and i found the syntax difficult, and i didn't really understand the complier errors I was getting, etc (the stuff at work wraps it all nicely for me). Mostly, the MFC stuff was easier to use, even though I knew it to be a worse implementation.
I'll have to spend some more time looking around / readin up on STL for future programs.
Thanks! 
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Yes, the compiler errors are a problem with STL, it can take a while to work out what is wrong. STL does NOT need wrappers though, it's just a case of learning the syntax so that when there is an error, you can work it out without trying to decipher the compilers errors.
Good luck !!!
Christian
Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002
During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002
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I'm using CMap because my MFC book talked about it, and it's a lot easier to understand than std::map, at least from looking at the examples.
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Fair enough. I used MFC containers for a while, and was only vaguely aware of vector. But I'd recommend you read my STL articles here on CP. The stl is not hard at all, the syntax is just unfamiliar - MFC containers follow MFC naming conventions which make them look more familiar, but in fact map and CMap work pretty much the same way. map is more powerful because of the way it interacts with other containers and algorithms.
You really owe it to yourself to look more closely at stl - as I said, it is far superior to the MFC alternative, which Microsoft only provided as a stopgap, expecting people to take up STL as soon as it became available in VC.
Christian
Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002
During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002
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try this:
template<>
inline UINT AFXAPI HashKey(CString& key)
{
return HashKey((LPCTSTR)key);
}
this will define a function that can convert your CString to a DWORD. just drop it in the header file where you define your map.
-c
bit, n:
A unit of measure applied to color. Twenty-four-bit color refers to expensive $3 color as opposed to the cheaper 25 cent, or two-bit, color that use to be available a few years ago.
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Thanks, that worked perfectly!
FYI, the arguments are <CString,CString&,BuddyInfo,BuddyInfo&>
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Why don't you use CMapStringToPtr or CMapStringToOb instead of fully generic CMap?
Tomasz Sowinski -- http://www.shooltz.com
*** Si fractum non sit, noli id reficere. ***
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My service is running on a computer i want to getsome information that are
is the computer in logoff state or not ?
if computer is in a logoff state
i want to login,if i have username,password and domain how to login programatically?
how many software are installed in a computer ?
i also want to get installed software list names?
is there any api available for this purpose?
r00d0034@yahoo.com
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lets say i have a regular expression (im using boost::regex)
([a-z],)*
and i Match() with "a," i get the following sub-expressions:
0) a, (the whole expression is first in boost::regex)<br />
1) a, (that's inside parentheses)
if i Match() with "a,b,c," however, i get:
0) a,<br />
1) c, (the last occurence of the things in parentheses)
i NEED to get all of the occurences though, like this:
0) a,<br />
1) a,<br />
2) b,<br />
3) c,
the problem is that, this is not a bug:
from
http://www.boost.org/libs/regex/syntax.htm#syntax[^]:
For example the expression "(ab)*" would match all of the string "ababab". The matching algorithms regex_match and regex_search each take an instance of match_results that reports what caused the match, on exit from these functions the match_results contains information both on what the whole expression matched and on what each sub-expression matched. In the example above match_results[1] would contain a pair of iterators denoting the final "ab" of the matching string.
so, can someone help me figure out how to get ALL of the matching occurences of the sub-expression?
thanks in advance
- Roman -
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If you want to match a string with an arbitrary number of letters and commas, you will not succeed I'm afraid.
What you want is a context-free grammar for your input "language". I'm not sure if you are familiar with BNF (Backis-Naur Form), but here's such a grammar notation:
<string> ::= <string> <letter_comma_group>
| (empty)
<letter_comma_group> ::= ['a'-'z'] ','
Regular expressions can only handle languages which follow something called regular grammars. Regular grammars cannot handle self reference - thus you will not be able to do what you want.
Please see Chomskys grammar hierarchy[^] for more information on this topic.
If you want to solve your problem, I suggest you look into writing a recursive descent parser http://www.wikipedia.org/wiki/Recursive_descent_parser[^]. But before you start implementing the grammar I mentioned above, please make sure you rewrite it to be LL(n) compatible. (Left-recursion in an LL(n) grammar is a big no-no! Try it and you'll find out why.
<string> ::= <letter_comma_group> <opt_string>
| (empty)
<opt_string> ::= <letter_comma_group> <opt_string>
| (empty)
<letter_comma_group> ::= ['a'-'z'] ','
Good luck!
--
Please state the nature of your medical emergency.
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There is no easy solution. How i've solved this in the past is to replace the matched pattern with something else, and loop, like this (perl) :-
$p="a,b,c,d,e,f,g,";
$matchcount=0;
while ($p=~s/([a-z],)
print ++$matchcount.": ".$1."\n";
Note that I lose the * from your pattern; you only want to match 1 at a time. =~ is the pattern operator in perl; // are delimeters around a pattern; s/// substitutes the first pattern with the second, ie nothing in this case. $1 is a special var which contains the first stored match.
Incidentally though, if your pattern really is as simple as a comma separated list, you may as well use a Split type function (theres bound to be one in your regexp library. In perl again:-
$p="a,b,c,d,e,f,g,";
@results = split (/,/ ,$p);
foreach $result (@results)
{
print $result."\n";
}
Hope that helps.
Signature space for rent. Apply by email to....
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Hi,
have you ever come across converting a *.wbmp (wireless bitmap) into normal bitmap or *.jpg and vice versa?
Any answer would be highly appreciated!
Thanks
R.
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Exactly what difference is there between a wireless bitmap and a normal bitmap? Please excuse my ignorance.
--
Please state the nature of your medical emergency.
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A wireless bitmap is, like the small brother of a normal bitmap, small, primitive, monochrom, and on top of all it is of different structure than *.bmp because no MS tool (including IE or Paint) is able to show it.
It is used on wireless devices (handy). WAP pages are written in so called WML (Wireless Markup Laguage) and they can only have references to *.wbmp pictures.
I would want to show these pics on IE if I knew how to convert them to human readable format.
R.
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this will do it: http://www.smalleranimals.com/thumb.htm
there's code on the codeproject site, too (i think), if you need that.
-c
bit, n:
A unit of measure applied to color. Twenty-four-bit color refers to expensive $3 color as opposed to the cheaper 25 cent, or two-bit, color that use to be available a few years ago.
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