array error

[nmn]

Hi
this array assignment gives the error of "lvalue required as left operand of assignment". Can someone explain to me why ? and how it can be resolved ?

Thanks much

[code]
IntArray a(10);
cout <<"low: " << a.low() << " high: " << a.high() << endl;
for(int i = a.low(); i <= a.high(); i++) {
a[i] =i * 10;
}

[Cubbi]

Show the definition of IntArray::operator[] - it sounds like it returns int by value.