FIX: Function Style Conversion Incorrectly Generates Errors (115705)

The information in this article applies to:

Microsoft Visual C++ for Windows, 16-bit edition 1.0
Microsoft Visual C++ for Windows, 16-bit edition 1.5
Microsoft Visual C++, 32-bit Editions 1.0
Microsoft Visual C++, 32-bit Editions 2.0
Microsoft Visual C++, 32-bit Editions 4.0
Microsoft Visual C++, 32-bit Editions 4.1
Microsoft Visual C++, 32-bit Editions 4.2
Microsoft Visual C++, 32-bit Editions 5.0
Microsoft Visual C++, 32-bit Editions 6.0

This article was previously published under Q115705

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 that this is a bug in the Microsoft products that are listed at the beginning of this article.

This problem was corrected in Microsoft Visual C++ .NET.

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;
};

Modification Type:	Minor	Last Reviewed:	7/5/2005
Keywords:	kbBug kbCompiler kbCPPonly kbfix kbNoUpdate KB115705 kbAudDeveloper