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No problem, in that case my recommendation not to use CString stands
"The secret of happiness is freedom, and the secret of freedom, courage."
Thucydides (B.C. 460-400)
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Umm... I'll have to agree. But you're a tough guy with that principle man. One must either know what CString is, or should not use it at all.
Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.
Codeproject.com: Visual C++ MVP
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Rajesh R Subramanian wrote: you're a tough guy
Not really. I certainly wouldn't apply that everywhere but CString is a bit if an exceptional case. CString abuse is so rife and so easy to fall into, and CString itself so potentially inefficient and error prone that I would say understand it or don't use it. I would not say the same for example for stl::vector or stl::map where misuse is less likely and understanding the source very much harder.
"The secret of happiness is freedom, and the secret of freedom, courage."
Thucydides (B.C. 460-400)
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thats why you are here.. to help people
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow Never mind - my own stupidity is the source of every "problem" - Mixture
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You
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Heh.
How's life going?
It is a crappy thing, but it's life -^ Carlo Pallini
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manju#123 wrote: sEndDate = (LPCSTR)CurrentDate;
Its not working ...
plz help me
the (LPCSTR)CurrentDate returns a constant TCHAR pointer. you can make it compilable by making sEndDate as const. For instance,
const _TCHAR *sEndDate;
If you want to modify the sEndDate , then you can use GetBuffer() as suggested by Matthew Faithfull, But dont forget to call ReleaseBuffer() .
Regards,
Jijo.
_____________________________________________________
http://weseetips.com[ ^] Visual C++ tips and tricks. Updated daily.
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Jijo raj wrote: the (LPCSTR)CurrentDate returns a constant TCHAR pointer
wrong. it returns a const char pointer.
(LP-C-T-STR) returns a const TCHAR*
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Typo. Actually I mean LPCTSTR . But a T means lot! Thanks for pointing it out.
Regards,
Jijo.
_____________________________________________________
http://weseetips.com[ ^] Visual C++ tips and tricks. Updated daily.
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Hi experts...
What about this?
_tcscpy(sEndDate,CurrentDate);
I am using this style. Is this wrong or right way?
modified on Tuesday, May 27, 2008 7:42 AM
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That makes a copy. It is fine sometimes (and the other times it is wrong).
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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Sir, just tell me where it will fail? I want to clear my confusion.
Thanks
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Whenever you need to actually modify CString 's internal buffer.
It is not a common usage, I know, but it is perfectly legal.
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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Thank you sir
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In general an explicit function call should be preferred over an implicit cast so it's not wrong but a GetBuffer() call would be better style and of course you should otherwise be using _tcscpy_s
"The secret of happiness is freedom, and the secret of freedom, courage."
Thucydides (B.C. 460-400)
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Matthew Faithfull wrote: it's not wrong but a GetBuffer() call would be better style
I don't agree. Implicit (or explicit) cast is not the same as GetBuffer() and you shouldn't use optionally one or the other: GetBuffer returns LPTSTR , while the cast returns LPCTSTR : the added C have his significance.
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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CPallini wrote: the added C have his significance.
Indeed it has and although I was talking general C++ style I do think it applies in this case. The CString impilcit cast returns LPCSTR because it isn't safe for it to hand out a pointer to its internal buffer without locking it but it also isn't good C++ for it to 'silently' give you a const pointer to something that is inherently not const. It's a compromise brought on by a compromised design.
"The secret of happiness is freedom, and the secret of freedom, courage."
Thucydides (B.C. 460-400)
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Well, let's try to get it from the CString 's consumer point of view:
(1) requesting, via (explicit) cast a pointer to a const buffer means: "OK, I need the buffer but I'll not change it".
(2) requesting via GetBuffer() a pointer to the internal buffer means: "I need the buffer to make all the weirdest things I know to it".
Clearly method (2) is a bit crude for a mere copy operation.
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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hi der, da getbuffr iz renamed in da latast sdk as GetBufferIKnowWhatImDoing()
Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.
Codeproject.com: Visual C++ MVP
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Indeed!
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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I strongly second that.
GetBuffer() is really to be forbidden for cast purpose
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Maxim Zarus wrote: Is this wrong or right way?
It's wrong since sEndDate has no storage space; it's just a pointer (to wherever).
"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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you mean, first allocate memory for sEndDate then i can use _tcscpy_s() .
its ok. i agree.
but is it also neccessary to allocate memory when CString::GetBuffer() has been used?
because i have seen in pervious post nobody ask to allocate memory for CString::GetBuffer() .
regards,
Maxim...
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Maxim Zarus wrote: you mean, first allocate memory for sEndDate then i can use _tcscpy_s().
Yes.
Maxim Zarus wrote: but is it also neccessary to allocate memory when CString::GetBuffer() has been used?
Not necessarily. It all depends on what you are going to be doing with the returned pointer.
Maxim Zarus wrote: because i have seen in pervious post nobody ask to allocate memory for CString::GetBuffer().
CString::GetBuffer() is very often misused.
"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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You can even use macrs A2W and W2A for conversions from multibyte-widechar and widechar-multibyte
For these macros you need to include "atlconv.h"
and also you need to write USES_CONVERSION macro before using these macros inside function.
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