Re: ATL COM library - BSTR question

"Ismo Salonen" <Ismo.Salonen@codeit.fi> ha scritto nel messaggio
news:evVJa6dTIHA.5516@TK2MSFTNGP02.phx.gbl...


Are these macros new additions to VS2008?

For VC++7.1 I developed something similar, based on ATL conversion helper
classes (CA2W/CW2A):

<code>
//----------------------------------------------------------------------------
// Class: CW2UEX
// Descr: Converts from Unicode UTF-16 (WideChars) to Unicode UTF-8
//----------------------------------------------------------------------------
template< int t_nBufferLength = 128 >
class CW2UEX
{
public:

   CW2UEX( LPCWSTR psz ) throw(...) :
     m_psz( m_szBuffer )
   {
      Init( psz );
   }

   ~CW2UEX() throw()
   {
      if( m_psz != m_szBuffer )
      {
        free( m_psz );
      }
   }

   operator LPSTR() const throw()
   {
      return( m_psz );
   }

private:
   void Init( LPCWSTR psz ) throw(...)
  {
     if (psz == NULL)
     {
       m_psz = NULL;
       return;
     }
     int nLengthW = lstrlenW( psz )+1;

     // One Unicode UTF-16 character could be converted
     // up to 4 UTF-8 characters
     int nLengthUtf8 = nLengthW * 4;

     if( nLengthUtf8 > t_nBufferLength )
     {
       m_psz = static_cast< LPSTR >( malloc( nLengthUtf8*
       sizeof( char ) ) );
       if (m_psz == NULL)
       {
         AtlThrow( E_OUTOFMEMORY );
       }
     }

     if (::WideCharToMultiByte( CP_UTF8, 0, psz, nLengthW,
        m_psz, nLengthUtf8, NULL, NULL ) == 0)
     {
        AtlThrowLastWin32();
     }
   }

public:
   LPSTR m_psz;
   char m_szBuffer[t_nBufferLength];

private:
   CW2UEX( const CW2UEX& ) throw();
   CW2UEX& operator=( const CW2UEX& ) throw();
};

typedef CW2UEX<> CW2U;
</code>

Giovanni