Re: Pointers

From:

David Wilkinson <no-reply@effisols.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Fri, 18 Aug 2006 07:40:00 -0400

Message-ID:

<u2BcEsrwGHA.4876@TK2MSFTNGP04.phx.gbl>

Alamelu wrote:

void classA::A()
{
unsigned char *pData; \\ Here pData is 0x000000

if(condition)
{
bEn = pLocal->B(pData); \\ Here pData is 0x000000

}

memcpy(pSomeData, pData, size) \\ Here pData is 0x000000

}

bool classB::B(unsigned char *pTemp)
{
pTemp = new unsigned char[100];

memcmpy(pTemp, pbuffer, size); \\ Here pTemp is 0x83551233

}

Since for pTemp memory is allocated in ClassB .. pData is not getting
updated properly

How do we overcome????????

How to get back the details in pTemp to pData??????????

I dont want to return pTemp... to the calling method... in that case it
works fine.. i want the return type to be bool only...

Alamelu:

You must pass the pointer by reference:

bool classB::B(unsigned char *& pTemp)
{
   pTemp = new unsigned char[100];
   if(pTemp != 0)
   {
     memcmpy(pTemp, pbuffer, size); \\ Here pTemp is 0x83551233
     return true;
   }
   return false;
}

But really in C++ you should not be using these C-style strings.

bool classB::B(CString& str)
{
   str = pbuffer
   return true;
}

David Wilkinson