BUG: Function Style Conversion Incorrectly Generates Errors

• The C/C++ Compiler (CL.EXE), included with:
  • Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5
  • Microsoft Visual C++, 32-bit Editions, versions 1.0, 2.0, 4.0, 4.1, 4.2, 5.0, 6.0

SYMPTOMS

When calling a class conversion function within a macro, as shown in the code below, the compiler may incorrectly generate the following errors:

error C2061: syntax error : identifier 'timeVal'
error C2066: cast to function type is illegal
error C2059: syntax error : ')'

RESOLUTION

Following are two possible workarounds for this problem:

• Use temporary variables to hold an intermediate result.

  
  unsigned int tmp1, tmp2;
  
  tmp1 = WORD(timeVal);
  tmp2 = WORD(dateVal);
  m_dwVal = MAKELONG(tmp1, tmp2); 



-or-


• Use a type cast operator instead of a conversion operator.

  
  m_dwVal = MAKELONG((WORD)timeVal, (WORD)dateVal); 

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

MORE INFORMATION

The following sample code demonstrates this problem.

Sample Code

/* Compile options needed: /c
*/ 

typedef unsigned short      WORD;
typedef unsigned long       DWORD;

#define LONG long

#define MAKELONG(low, high) ((LONG)(((WORD)(low)) |  \ 
                (((DWORD)((WORD)(high))) << 16)))

class CMyDate
{
public:
   operator WORD()
   {
      return m_wVal;
   }

private:
   WORD m_wVal;
};

class CMyTime
{
public:
   operator WORD()
   {
      return m_wVal;
   }

private:
   WORD m_wVal;
};

class CMyDateTime
{
   CMyDateTime(CMyDate dateVal, CMyTime timeVal)
   {
      m_dwVal = MAKELONG(WORD(timeVal), WORD(dateVal));

   // This call works in both, even though it is identical.

      m_dwVal= MAKELONG(timeVal.operator WORD(), dateVal.operator
               WORD());
   }

 private:
   DWORD m_dwVal;
};

 

Additional query words: kbVC400bug 8.00 8.00c 9.00

Keywords : kbCompiler kbCPPonly kbVC kbVC100bug kbVC200bug kbVC400bug kbVC410bug kbVC420bug kbVC500bug kbVC600bug
Version : winnt:1.0,2.0,4.0,4.1,4.2,5.0,6.0
Platform : winnt
Issue type : kbbug