Re: CArray

"David Webber" <dave@musical-dot-demon-dot-co.uk> ha scritto nel messaggio
news:uGF2YPtHIHA.4880@TK2MSFTNGP03.phx.gbl...


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
defined.

So, I would do something like this:

<code>

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

  StringMatrix strings;
</code>

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.

<code>

  class StringMatrix
  {
  public:
    StringMatrix();
    explicit StringMatrix( int rows, int columns );

    ...

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

    ...

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

    int m_rowCount;
    int m_columnCount;

    int GetIndex( int row, int col ) const;
  };

</code>

Get and Set could be implemented something like this:

<code>

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

    CString StringMatrix::Get( int row, int col ) const
    {
        return m_strings.at( GetIndex( row, col ) );
    }

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

</code>

The fact that Set returns a reference to the object, allows chained call,
e.g.:

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

Giovanni