In article <C79zBu.By2@knot.ccs.queensu.ca> jinke@sparky.phy.queensu.ca (Ke Jin) writes:
>     friend T& operator [](ARRAY& a, int pos) {

Yes, except ARM requires operator[] to be a member function.
Same difference, otherwise.

  I have created an array template to provide bounds checking like so:

template T
class ARRAY
{
  int size;
  T* data
  public:
  ARRAY( int s )
  {
    size = s;
    data = new T[s];
  };
T operator []( int pos )
  {
    if ( pos < 0 || pos >= s )
      cerr << "Array out-of-bounds error!\n";
    else
      return( data[ pos ] );
  };



This is nifty, and for my final compile I can take out the bounds checking
and make it normal arrays.  However, I find I can't do this:

intarray[ a ] = i;

i have to use a function like this:
intarray.insert( a , i );

Which is okay, but I prefer the former.  Anyone know how to do this?

dave
----------------------------
"The more one knows the less one beleives"

In article <93139.003354U34465@uicvm.uic.edu>, David James Alexander
Hanley <U34465@uicvm.uic.edu> writes:

[description of bound-checked array deleted]

|>  However, I find I can't do this:
|>
|> intarray[ a ] = i;
|>
|> i have to use a function like this:
|> intarray.insert( a , i );
|>
|> Which is okay, but I prefer the former.  Anyone know how to do this?
|>
|> dave
|> ----------------------------
|> "The more one knows the less one beleives"

What about using a reference parameter? Like this:


 T& operator []( int pos )
   {
     if ( pos < 0 || pos >= s )
       cerr << "Array out-of-bounds error!\n";
     else
       return( data[ pos ] );
   };

I think that will do the trick.


Jan

In article <93139.003354U34465@uicvm.uic.edu> David James Alexander Hanley <U34465@uicvm.uic.edu> writes:
>  I have created an array template to provide bounds checking like so:
>
>template T
>class ARRAY
>{
>  int size;
>  T* data
>  public:
>  ARRAY( int s )
>  {
>    size = s;
>    data = new T[s];
>  };
>T operator []( int pos )
>  {
>    if ( pos < 0 || pos >= s )
>      cerr << "Array out-of-bounds error!\n";
>    else
>      return( data[ pos ] );
>  };
>
>
>
>This is nifty, and for my final compile I can take out the bounds checking
>and make it normal arrays.  However, I find I can't do this:
>
>intarray[ a ] = i;
>
>i have to use a function like this:
>intarray.insert( a , i );
>
>Which is okay, but I prefer the former.  Anyone know how to do this?
>
>dave
>----------------------------
>"The more one knows the less one beleives"

You can try to overload the operator [] with a friend function instead of a `
member one. The followin code worked under gcc 2.2.2.

template <class T>
class ARRAY
{
     int size;
     T* data;
  public:
     ARRAY( int s ) { size = s; data = new T[s]; };
     friend T& operator [](ARRAY& a, int pos) {
       if ( pos < 0 || pos >=a.size);
       cerr << "Array out-of-bounds error!\n";
       else
       return(a.data[pos]);
                     };
};

good luck.

Ke Jin
--
Andrew Ke Jin      | I speak for myself   not for God. | (613)-545-2723
Physics Department | This is not the thesis or  a law. | jinke@sparky.
Queen't University | Don't blame   if something wrong, |  phy.queensu.ca
Kingston,  K7L 3N6 | Just believe you're smart not me. |