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You're right (and I'm blind  ).
A2WBSTR seems more flexible: you may convert only a chunk of the original ANSI string.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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Thanks CPallini,
Question answered.
regards,
George
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I came across this use of the "new" keyword in a library recently. I had to look it up to see what was going on. Apparently its valid, I've just never seen it before in any code examples, books, articles, etc.
If you write a custom new operator, you can write it to take an extra argument. When callers use the new keyword they supply an additional argument which gets passed to the new operator.
So you can call
MyClass* instance = new 128 MyClass;
This creates an instance of MyClass as expected but when invoking the custom new operator passes along the argument 128.
Anyway, I'm just curious if anyone else has seen or used this. It caught me off guard.
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Have not seen it done like that before, but I could see it being used for things like allocating additional memory at the end of the object. Remember how variable-length structures like DDEDATA, PDH_COUNTER_INFO and some device driver ones worked?
Also for custom heap management - I want this object on this heap and that object created on on that heap, or created in a pre-reserved (shared?) block of memory.
Peace!
-=- James Please rate this message - let me know if I helped or not!<hr></hr>If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
See DeleteFXPFiles
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Dave Calkins wrote: Anyway, I'm just curious if anyone else has seen or used this. It caught me off guard.
Placement new, perhaps?
"Love people and use things, not love things and use people." - Unknown
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Placement new required the use of parenthesis:
new (value) Type Although now that I think about it, you may be correct. I think that placement new is the only way to pass parameters to new...?
Peace!
-=- James Please rate this message - let me know if I helped or not!<hr></hr>If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
See DeleteFXPFiles
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James R. Twine wrote: I think that placement new is the only way to pass parameters to new...?
AFAIK, you can override the new operator. I think that's what is done for the MFC: the file and line are passed to the new operator in order to track memory leaks easier.
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Yep - yer right...
-=- James Please rate this message - let me know if I helped or not!<hr></hr>If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
See DeleteFXPFiles
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Cedric Moonen wrote: AFAIK, you can override the new operator. I think that's what is done for the MFC
GDI+ does it too
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.freetls.fastly.net/script/Forums/Images/coffee.gif)
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Correct. As I said, I had to look it up to see what was going on and discovered placement new in the docs. My point was just that I'd never seen this used in code before and was curious if anyone else had. It just seems a bit esoteric
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Hi all
I am facing a strange issue. I call RegCreateKeyEx to create a key in the Vista registry , but it fails . Could any one please help me find out what I am missing ...?
HKEY hk=NULL;
char tmp_Path[256] = "Software\\Company\\PreferredNos\\no_device";
dwResult = RegCreateKeyEx(HKEY_LOCAL_MACHINE,
tmp_Path,
0,
NULL,
REG_OPTION_NON_VOLATILE,
KEY_ALL_ACCESS,
NULL,
&hk,
NULL) ;
if(hk!=NULL)
RegCloseKey(hk);
if ( dwResult != ERROR_SUCCESS )
{
SpiDebug ((DBG_INFO , _T("TSP"), _T(" RegCreateKeyExFAILED")))
}
redindian
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Did you check the return value?
Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.
Codeproject.com: Visual C++ MVP
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Do you have the correct access rights ?
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dharani wrote: I call RegCreateKeyEx to create a key in the Vista registry , but it fails .
Straight from the docs:
If the function fails, the return value is a nonzero error code defined in Winerror.h. You can use the FormatMessage function with the FORMAT_MESSAGE_FROM_SYSTEM flag to get a generic description of the error.
"Love people and use things, not love things and use people." - Unknown
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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dharani wrote: KEY_ALL_ACCESS
Never do that - only request the access levels that you really need.
Peace!
-=- James Please rate this message - let me know if I helped or not!<hr></hr>If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
See DeleteFXPFiles
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What was return value of dwResult ?
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Hi all,
Actually i want to find out that particular path exist or not, for that i am using _accessApi. like this
TCHAR CurrentPath [ MAX_PATH ] ;
GetTempPath(MAX_PATH, CurrentPath);
_tcscat(CurrentPath,_T("$insert\\new folder"));
_access(CurrentPath,NULL);
but compiler is giving this error
error C2664: '_access' : cannot convert parameter 1 from 'TCHAR [260]' to 'const char *'
how could i remove this
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You should use _taccess instead (it is also a macro that doesn't depend if UNICODE is declared or not).
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i am creating a user accound using NetUserAdd api ,
i need to map the user to a group ,only group name is supplied
NetUserSetGroups is used for this ..but i got return value 2200
0x8ac ...Any body have any idea of this ....???
vineesh
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vineeshV wrote: NetUserSetGroups is used for this ..but i got return value 2200
Which equates to NERR_AlreadyLoggedOn. That's odd.
"Love people and use things, not love things and use people." - Unknown
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Hi all,
Incase of Dialog we use DoModal for calling dialog.
anyone can tell me that what can i use for calling formview.
or what can i use in place of OK(), because OK() is not working for formview.
thanks in advance.
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Do you mean formview as in CFormView, in MFC? If so, you let MFC do the heavy lifting. Internally, it will call CreateDialog, etc, but you don't need to worry about that.
To see how it works, make a fresh MFC project using AppWizard, and choose form view as your view type. Then have a look at the CMyApp::InitInstance member function to see how little work you need to do.
Good luck,
Iain.
Iain Clarke appears because CPallini still cares.
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ThatsMe. wrote: anyone can tell me that what can i use for calling formview.
This imples that you are using either an SDI or an MDI application. Correct?
ThatsMe. wrote: or what can i use in place of OK(), because OK() is not working for formview.
Since an OK button is present, are you wanting a dialog-based application instead?
To mix the two just seems a bit out of the ordinary.
"Love people and use things, not love things and use people." - Unknown
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Hi all ,
when i run my application,or click for open any form then it gives this error "Windows has triggered a breakpoint in project.exe.
This may be due to a corruption of the heap, and indicates a bug in project.exe or any of the DLLs it has loaded.
The output window may have more diagnostic information"
how can i remove it please tell me.
thanks in advance.
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It feels like repetition, but anyway, see here[^]
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