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I had a code that used #include "fstream.h" in VC6.In the code i used
ifstream file ;//used file for opening and manipulating.
But when i opened the code in VC8 first it showed
"fatal error C1083: Cannot open include file: 'fstream.h': No such file or directory"
Then i gave #include "fstream" as i saw in msdn.But now it is saying
"error C2065: 'ifstream' : undeclared identifier"
What is the mistake?
Thankyou
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it should be
#include <fstream>
and you probably need
using namespace std;
or to declare it as
std::ifstream
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I'd like to write an app runs like the wallpaper, it lays on desktop always, just like wallpaper, but it can also get mouse/keyboard messages, it that possible?
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Good question.
There should be a way to do it (I do not know). I suspect that you will need to subclass the desktop window; meaning that all messages go through your app. There are articles at CP on code that does that, so they can do their customized look for the interface. Depending on what you are trying to accomplish, it could be some what more difficult than that but it is probably not.
INTP
"Program testing can be used to show the presence of bugs, but never to show their absence."Edsger Dijkstra
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You can create an application with z-order bottom to do so. Or another idea is create window with parent as desktop list control. I am not so sure about the fine result, but I think it should work...  Have a try..
- NS -
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yes )
Really!
GetDesktopWindow() api can be used for this purpose.
Good Luck!
dlfkgj lsdfkglfkgjlfgl jldfk fldkk jk
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Hi all,
How do I check if a string is valid for saving? for example string A contains document.doc that is valid but what if it contains ????.doc that is not valid, how can I check if it is valid or not?
Here is my code
if (!sName.empty()){
strAttachment.append(sName);
pAttach->SaveAs(strAttachment.c_str());
}
I need to add a checker before saving.
Thanks,
Jj
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My first thought was to look it up; then I just tried to change a file name by adding a known invalid character and looked at the error message (seemed simpler). According to the message a file name under Windows XP can not contain \/:*”<>|. Therefore just scan the name for those characters, but I would still double check through the help system or online.
If you have the option of using regular expressions (not necessary), then you could write one to validate the string.
Good Luck!
INTP
"Program testing can be used to show the presence of bugs, but never to show their absence."Edsger Dijkstra
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Hi,
Hope somebody can help me.
I'm working on a program and i need to use VIPS API.
This is an image processing API.
Has somebody used this API on MFC?
Is it possible to use this on MFC?
I have followed online installation, but i can't find documentation on how to use it in a program. All it says is to include this part in a program
#include <vips/vipscpp.h>
vips.h and vipscpp.h is already included in the solution but when build,
Cannot open include file: 'vips/vipscpp.h' : No such file or directory
Any comment will be appreciated.
Thank you.
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This really bothers me.
See, I have a class and two variables of the same class, CBuffer, named Buffer<t1> and RetBuf<t2>.
So, there's a line of code that says Buffer = RetBuf (class CBuffer has an overloaded operator = that takes another CBuffer<t3>& as argument).
So even in debug, the compiler generates the following code:
004B1E48 mov eax,dword ptr [ebp+18h]
004B1E4B mov dword ptr [ebp+10h],eax
004B1E4E mov ecx,dword ptr [ebp+1Ch]
004B1E51 mov dword ptr [ebp+14h],ecx
WHICH IS COMPLETELY WRONG! Does anyone know why this may happen and how to fix such a thing? I already tried a rebuild without success.
All we long-time developers should know that unless there's an overload that takes a CBuffer<t3>& as argument, this operation is impossible. But there is one such overload, though, although the compiler does not generate code to call it, but instead perform pointer assigns! It's like it's thinking they're pointers, and therefore trying to assign the RetBuf pointer to the Buffer pointer, which again is not possible since there's no cast and they're different types! This boggles my mind! What IS the compiler doing?!
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Where's code code for CBuffer? A snippit of a machine code with no context isn't much to work with!
Steve
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What led you to the conclusion that your code was wrongly compiled ?
Was it not doing what you wanted ?
Can we see the C++ code ?
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What indeed? That it doesn't call the overloaded operator function is quite enough.
Showing all the code would be pretty long and boring and irrelevant, so I'll show the important snippets of the declaration/definition of the variables and the class.
template< class T1, class T2><br />
long GetRegValuePtrNew(const char* strKey, const char* strName, CBuffer< T1> Buffer, CBuffer< T2> RetBuf = (T2*)THROW_ERROR, DWORD* pType = NULL) throw(...)<br />
{<br />
...<br />
Buffer = RetBuf;<br />
...<br />
}<br />
<br />
template< typename T> class CBuffer<br />
{<br />
...<br />
template< typename T2> void operator = (CBuffer< T2>& rBuffer);<br />
...<br />
};<br />
There's the basic declaration, so the obvious thing is that the compiler should generate code that calls CBuffer::operator =, but it doesn't, as you can see from the asm snippet I gave you.
This is all the relevant parts of the code, but I can post the whole function/class if it's necessary. It's just that it would be so long.
I also want to made it clear that I intentionally put spaces after a < since otherwise it's interpreted as HTML code and not shown. In REAL code I would NEVER do that, since I HATE it, it looks POOR. Just wanted to say that 
EDIT:
Actually, I seem to have fixed the problem.
The problem was that the compiler was confused, but it still shouldn't have generated faulty code. It should complain, should it not?
Consider this:
As you saw above, the assignment operator takes a CBuffer of a DIFFERENT type than the type of the actual class (it takes T2 instead of T).
In the above template, T1 and T2 = UINT64, the same type.
Adding the following:
void operator = (CBuffer<T>& rBuffer);
...Fixes the problem. It seems the compiler gets confused and cannot interpret T2 as T (so if there's a var of CBuffer< UINT64>, the assignment operator can't take a CBuffer< UINT64> as argument, because it's the same type as the class type T).
I got around it by adding an additional operator that takes the class's type T (CBuffer< T>) as argument and now it works. Of course, this shouldn't really be, AFAIK.
Here is the new code:
void operator = (CBuffer<T>& rBuffer)<br />
{<br />
Assign(rBuffer);<br />
}<br />
<br />
template<typename T2> void operator = (CBuffer<T2>& rBuffer)<br />
{<br />
Assign(rBuffer);<br />
}<br />
<br />
template<typename T2> void Assign(CBuffer<T2>& rBuffer)...<br />
As plainly visible, both overloads call Assign, which takes a new template type T2 as argument, and both functions (well, I only tested the first, though) call the Assign function just fine.
But even so, if there's no suitable overload, it should call the copy constructor, which again, it didn't. This seems like a compiler bug.
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Tydia-kun wrote: CBuffer< T1> Buffer
Tydia-kun wrote: CBuffer< T2> RetBuf
Tydia-kun wrote: Buffer = RetBuf;
Buffer and RetBuf are different types
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Yes, they are and that's the whole point of the overloaded assignment operator (=). It takes a CBuffer of different type (or the same type) and copies the data from that buffer into its own buffer.
But somehow the compiler didn't understand that.
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Don't you need to implement template specialisatioin for that ?
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Templates are templates - they can be of any type. That's why the overloaded assignment operator takes a new template type of T2. That's the power of templates.
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what if you have
CBuffer<string> bufferOfString;
CBuffer<int> bufferofInt;
bufferOfString = bufferOfInt;
don't you need specialisation to know how to convert a CBuffer<int> to a CBuffer<string> ? It's not just a memcpy or member-member copy.
I'm just curious, I'm not very familiar with template constructs.
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That wouldn't work unless you overlord a operator = (CBuffer<int>) or simply make a template operator = such as template<typename T2> operator = (CBuffer<T2>).
That way, the compiler can call the overloaded operator = and pass bufferOfInt to it with T2 = int.
Memcpy is a very stupid (and dangerous) way of assigning a class to another class since classes are built around handling its own memory and variables.
If you read about templates, then you know that you can specify a type for a template and the compiler will generate a function with that type when the template function is invoked. Take for example
template<typename T2> operator = (CBuffer<T2>)
When you do bufferOfString = bufferOfInt, it generates an overloaded function
operator = (CBuffer<int>)
And calls it. That's it.
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Tydia-kun wrote: Yes, they are and that's the whole point of the overloaded assignment operator (=).
No its not. The point of the assignment operator is to assign the value of one object to the value of another. For that to be possible the objects have to be of the same type. Templates are nothing but code generation. When you declare vector<int> and vector<string> they are completely differnt types and have no common interface. If you want to perforam assignment between the two you have to write a specific operator. You cannt write a generic one
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It's the whole point of MY overload operator =, I meant.
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You do have some other problems you need to address. The argument to your overloaded method should be constant and it should return a reference to the left hand side of the argument so you can do things like: “a1 = a2 = a3”.
Keep your eyes open for implicit conversions, which is what you’re originally problem sounded like.
INTP
"Program testing can be used to show the presence of bugs, but never to show their absence."Edsger Dijkstra
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Constant? As in non-template function? If that's the case, that's a no-go.
I also added a return type of CBuffer<t>& to return *this, so it should work with a=b=c now, I think.
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I have a SDI application.
I also have a class derived from CDialog which has no no border but some control on it. I want to use this borderless dialog as a toolbar.
Is it possible to dock this dialogbox into the SDI main frame. Frame window has EnableDocking, DockControlBar function which takes CControlBar* as an argument, but my one is derived from CDialog with attached with a dialog resource.
Also CDialog class does not have a EnableDocking method.
So, I was wondering is there any way to dock a dialog with a frame window.
Any idea will be appreciated.
Thank you
msc
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