Re: CArray

"Giovanni Dicanio" <>
Sun, 4 Nov 2007 16:51:32 +0100
"David Webber" <> ha scritto nel messaggio

"mido1971" <> wrote in message

how can i use a CArray in multidimensional like CString [2][2] and how
can i
insert the data

thanks for help

Very schematically:

class CMyArray1D : public CArray<CString, CString &>
   // Write members including copy constructor and = operator

class CMyArray2D : public CArray<CMyArray1D, CMyArray1D &>
   // Write members including copy constructor and = operator

Dave: you correctly answered OP's question, which asked about CArray.

What I don't like about CArray, is the fact that I need to write copy ctor
and operator=.

I think that if the OP uses std::vector, there is a default copy mechanism
implemented, i.e. copy ctor and operator= don't need to be explicitly

So, I would do something like this:


  typedef std::vector< CString > StringArray;
  typedef std::vector< StringArray > StringMatrix;

  StringMatrix strings;

or better, I would implement the 2D matrix using a single array (1D), but I
would define a pair of methods like Get and Set, which take in input two
integers (row and column) and access in read/write the given string element.


  class StringMatrix
    explicit StringMatrix( int rows, int columns );


    CString Get( int row, int col ) const;
    StringMatrix & Set( int row, int col, const CString & s );


    typedef std::vector< CString > StringArray;
    StringArray m_strings;

    int m_rowCount;
    int m_columnCount;

    int GetIndex( int row, int col ) const;


Get and Set could be implemented something like this:


    // Given (
    inline int StringMatrix::GetIndex( int row, int col ) const
      return ( row * m_columnCount + col );

    CString StringMatrix::Get( int row, int col ) const
        return GetIndex( row, col ) );

    StringMatrix & StringMatrix::Set( int row, int col, const CString & s )
    { GetIndex( row, col ) ) = s;
        return *this;


The fact that Set returns a reference to the object, allows chained call,

  aStringMatrix.Set( 1, 3, _T("Hello") ).Set( 2, 5, _T("World") ).Set( 0, 3,
_T("Ciao") );


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