llewelly <ll*********@xmission.dot.com> wrote in message news:<86************@Zorthluthik.local.bar>...
Irrwahn Grausewitz <ir*****@freenet.de> writes:
Irrwahn Grausewitz <ir*****@freenet.de> wrote in
<l9********************************@4ax.com>:
Well, for square arrays i and j are interchangeable, as long as
you use them in a consistently, but it works for all n-dimensional ^^^^<del>
int *arr = (int*) malloc( ZDIM * YDIM * XDIM * sizeof *arr );
^^^^^^
Damn, now I've copied this stupid cast!
That's ok. Weirdos who compile your code on boxen where int and int*
are not the same size deserve undefined behavior. Especially if
you forgot to include a header. Remember, all the world is a
wintel32.
(Note to c.l.c++ readers: that cast isn't necessary or safe in C++
either; the alternatives are:
vector<int> arr(ZDIM * YDIM * XDIM);
int *arr= new [ZDIM * YDIM * XDIM * sizeof *arr];
int *arr= static_cast<int*> malloc( ZDIM * YDIM * XDIM * sizeof *arr );
)
IMHO, a better C++ alterantive would be to use either a
vector<vector<int> > object or even better yet, the following dynamic
2 dimensional array object:
template < class T, int ROW_T = 0, int COL_T = 0 >
class dynamic_2d_array
{
public:
dynamic_2d_array(int row, int col):m_row(row),m_col(col),
m_data((row!=0&&col!=0)?new T[row*col]:NULL){}
dynamic_2d_array():m_row(ROW_T),m_col(COL_T), m_data(new
T[ROW_T*COL_T])
{if (!COL_T || !ROW_T) {int x[ROW_T] = {{ROW_T}};int y[COL_T] =
{{x[0]}};}}
~dynamic_2d_array(){if(m_data) delete []m_data;}
T* operator[](int i) {return (m_data + (m_col*i));}
T const*const operator[](int i) const {return (m_data +
(m_col*i));}
private:
const int m_row;
const int m_col;
T* m_data;
};
See following link for usuage example and for vector<vector<type> >
example:
http://axter.com/faq/topic.asp?TOPIC..._ID=4&CAT_ID=9