C / C++ / MFC

Re: Windows has triggered a breakpoint in exe.......

19-Jul-12 22:24

Try using the c_str()[^] member function to get the data from the string parameters.

One of these days I'm going to think of a really clever signature.

Andraw11123-Jul-12 3:44

Re: Windows has triggered a breakpoint in exe.......

23-Jul-12 3:44

Richard, thanks for your suggestion.

Yes, if in the calling side I pass string.c_str() value
string xx = "calling...";

func(xx.c_str());

and in the function definition side I define function as:
func(const char* str){}

everything is fine.

But my project has hundreds functions, it was created in C++ 6.0, now I wish to migrate it to VS2008, if I have to modify all the function definition and modify all the places to function call, that's a big work.

Is there any better way to solve this issue? Thanks!

Richard MacCutchan23-Jul-12 4:30

Re: Windows has triggered a breakpoint in exe.......

23-Jul-12 4:30

I do not know of any simple way other than "Find & Replace in Files" (Ctrl+Shift+H). It's a pity that you created the functions to accept char* parameters rather than string object references, then you would not have had to change in so many places.

[edit]
It is, of course, always possible, that the 'bug' in your code will not be fixed by these changes, but is connected to something else. Make sure that you are actually fixing the right problem before you make all these changes.
[/edit]

One of these days I'm going to think of a really clever signature.

Andraw11123-Jul-12 5:36

Re: Windows has triggered a breakpoint in exe.......

23-Jul-12 5:36

I am testing to pass std::string by reference instead of std::string, it works fine. so in this case, all I need to do are modify all the function siguratures with std::string as argument, that saves a lots of time.

Thanks!

Richard MacCutchan23-Jul-12 5:45

Re: Windows has triggered a breakpoint in exe.......

23-Jul-12 5:45

I also just noticed that in one of your earlier posts you are using std::strings for string constants. This is a waste of time as you are just adding extra code to copy the constant character value into a std::string in order to pass it to some function.

One of these days I'm going to think of a really clever signature.

Andraw11123-Jul-12 6:24

Re: Windows has triggered a breakpoint in exe.......

23-Jul-12 6:24

Yes, this issue is caused by pass std::string between EXE and DLL.

When I search the solution from internet, all say that you canno pass std::string between DLLs, you'd better pass C-style character string, that's way I convert std::string to char*.

Now since passing std:: string by reference can solve the issue, that's best.

Richard MacCutchan23-Jul-12 7:14

Re: Windows has triggered a breakpoint in exe.......

23-Jul-12 7:14

Andraw111 wrote:
this issue is caused by pass std::string between EXE and DLL.

I'm sure it's more than just that.

Andraw111 wrote:
you canno pass std::string between DLLs

If that were true you would not be able to pass any objects between DLLs.

One of these days I'm going to think of a really clever signature.

Stephen Hewitt20-Jul-12 6:55

Stephen Hewitt

20-Jul-12 6:55

Looks like you're crashing because of heap corruption. The crash is almost certainly happening in the "Class1* obj = new Class1();" line (it's common for the line number to indicate the line after actual call in question), the "dbgheap.c" all but proves it.

With heap problems the actual root cause (when the heap got corrupted) and the resulting crash (in your case when the heap manager detects it) can be separated but quite some time, which makes it difficult to debug.

I'll take a wild quess at the cause however:
Looks like the new statement with allocates the object is in the DLL. How is it deleted? By a delete statement in the DLL's client? If so try moving it into the DLL where it belongs:

void DeleteCase1Obj(Class1 *obj)
{
   delete obj;
}

Replace all deletes of this object in the client with calls to this function which is exported from the DLL.

Steve

error C2491: 'XXX'::entries' : definition of dllimport function not allowed

Andraw11119-Jul-12 4:51

Re: error C2491: 'XXX'::entries' : definition of dllimport function not allowed

19-Jul-12 4:51

Hi, dear all,

I have a DLL file created in C++ 6.0, now move to VS2008 and get compile error.

in header file:

#define XXXPORT __declspec(dllimport)

template <class TP> class XXXPORT TPtrList
{
public:
int entries(bool deleted = false) const;

TP *operator[](int n);
const TP *operator[](int n) const;
..............
..............

}

in .cpp file

template <class TP>
inline int TPtrList<TP>::entries(bool deleted) const
{
.........
}

template <class TP>
inline TP *ABSTPtrList<tp>::operator[](int n)
{
.........}

In C++, they are fine, but in VS2008, When I compile it, I got

error C2491: 'TPtrList<TP>'::entries' : definition of dllimport function not allowed

error C2491: 'TPtrList<TP>::operator []' : definition of dllimport function not allowed

What cause this problem? Thanks!

Albert Holguin19-Jul-12 5:09

Albert Holguin

19-Jul-12 5:09

This looks like you're defining the functions when doing the dll import... when all you should have is function prototypes. You probably want to define XXPORT up there to say dllexport.

Re: error C2491: 'XXX'::entries' : definition of dllimport function not allowed

Andraw11119-Jul-12 5:35

error C2679: binary '!=' : no operator found which takes a right-hand operand of type 'int' In VS2008

19-Jul-12 5:35

Yes, you are right.

I just change to dllexport, then I can add function implementation to it, so can be used by other class inside this DLL.

Thanks!

Andraw11119-Jul-12 4:20

Re: error C2679: binary '!=' : no operator found which takes a right-hand operand of type 'int' In VS2008

19-Jul-12 4:20

Hi, dear all,

I create a class name Point2D to store coordinate value, with "<" and "==" two operators overloadings.

Then create a type based on it as:

typedef std::vector<Point2D*> Point2D_Vector;

Point2D_Vector PointVector;

Then add some data to PointVector.

When I loop the vector:

Point2D_Vector::iterator itr;
for (itr=PointVector.begin(); itr!=PointVector.end(); itr++)
if (itr != 0)
delete *itr;

They work fine in C++6.0, now when I try to compile it in VS2008 I got the error message in if(itr != 0) line:

error C2679: binary '!=' : no operator found which takes a right-hand operand of type 'int' (or there is no acceptable conversion)

How can I solve this issue? Thanks!

C^hris L^osinger19-Jul-12 4:27

C^hris L^osinger

19-Jul-12 4:27

C++

if ((*itr)!=0)

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Re: error C2679: binary '!=' : no operator found which takes a right-hand operand of type 'int' In VS2008

Stephen Hewitt19-Jul-12 4:27

Stephen Hewitt

19-Jul-12 4:27

The statement itr != 0 makes no sense. Even when it compiled in VC6 it wasn't doing what it looks like you intended (to stop deleting a NULL pointer). You probably mean this:

if (*itr != 0)

Also, deleting a NULL pointer is safe in C++ (it does nothing). The check is not needed and it potentially makes the code less efficient as the compiler inserts code to check for this automatically.

Steve

Re: error C2679: binary '!=' : no operator found which takes a right-hand operand of type 'int' In VS2008

Andraw11119-Jul-12 4:35

19-Jul-12 4:35

Thanks, Chris and Steve, it can be compiled now.

c++ code

phineas kimathi19-Jul-12 2:46

phineas kimathi

19-Jul-12 2:46

a code to change string to uppercase using integer values within the code.

Richard MacCutchan19-Jul-12 3:21

19-Jul-12 3:21

There are built in library and MFC functions to perform this. Please explain what you mean by "change string to uppercase using integer values"?

One of these days I'm going to think of a really clever signature.

Rajesh R Subramanian19-Jul-12 3:34

Rajesh R Subramanian

19-Jul-12 3:34

Hint: There's an offset of 32 between lower and upper cased letters. For example, the ascii value (int) of lower case 'c' is 99, and the same of upper case 'C' is 67.

"Real men drive manual transmission" - Rajesh.

Software_Developer19-Jul-12 6:52

Software_Developer

19-Jul-12 6:52

The integer difference between a lowercase char and a uppercase char when subtracted is 32.
simply subtract the lowercase by 32 to get a uppercase char.

#include <stdio.h>
#include <string.h>

int main(void)
{
	char strchr[32] = "the quick fox";
	int strlength=strlen(strchr);

        printf("Before\n" );
	printf("%s\n\n", strchr);
 
	for (int i=0; i<strlength; i++) 
	{
		if((strchr[i] >= 97) && (strchr[i] <= 122)) 
		{
			strchr[i] = strchr[i] -32;
			
		}
	}
        printf("After\n" );	 
	printf("%s\n\n", strchr);

return(0);

}

Richard MacCutchan19-Jul-12 22:20

19-Jul-12 22:20

Using hexadecimal rather than decimal integer values makes the code much more readable.

One of these days I'm going to think of a really clever signature.

David Crow20-Jul-12 2:29

David Crow

20-Jul-12 2:29

TopCoder23 wrote:
char strchr[32] = "the quick fox";

I would consider a different variable name as strchr is the name of a CRT function.

TopCoder23 wrote:
if((strchr[i] >= 97) && (strchr[i] <= 122))

What about:

if (islower(strchr[i]))
    strchr[i] = toupper(strchr[i]);

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Error happen when open file while migrate VC++ 6 to VS2008

Software_Developer20-Jul-12 3:30

Software_Developer

20-Jul-12 3:30

You're right about strchr() . and islower(). http://www.cplusplus.com/reference/clibrary/cstring/strchr/[^]

Andraw11118-Jul-12 9:16

Re: Error happen when open file while migrate VC++ 6 to VS2008

18-Jul-12 9:16

Hi,dear all,

I have a project created using C++ 6.0. Now I need to update it to VS2008, now I have a problem when I try to open a file.

In C++ 6.0
#include <fstream.h>
ifstream INPFile(INPFileName, ios::nocreate);

In VS2008

#include <fstream>
ifstream INPFile(INPFileName, ios::nocreate);

the second line get the following error:
Error 23 error C2039: 'nocreate' : is not a member of 'std::basic_ios<_Elem,_Traits>'

Error 24 error C2065: 'nocreate' : undeclared identifier

If I change the second line to the following:

ifstream INPFile(INPFileName)

then get new error as following
error 2248: 'std::basic_ios<_Elem,_Traits>::basic_ios' : cannot access private member declared in class 'std::basic_ios<_Elem,_Traits>'

How can I solve this issue?

Thanks!

Albert Holguin18-Jul-12 9:47

Albert Holguin

18-Jul-12 9:47

This talks about the reason for the first error:
http://www.devx.com/tips/Tip/14544[^]

After your change however, the error about the private member doesn't make sense, you probably need to show a bit more of your code.

Re: Error happen when open file while migrate VC++ 6 to VS2008

Andraw11118-Jul-12 10:01