/*
  array3a.cpp 

  same as array3.cpp but with ctor and dtor

*/

#include <iostream>
using namespace std;


class IntArray {
public:
  IntArray();
  ~IntArray();
  void setSize( size_t value );
  size_t getSize();
  void setElem( size_t index, int value );
// member functions can be declared inside the class:
  int getElem( size_t index ) {
    if (( index < -0 ) || ( index >= numElems )) {
      cerr << "bad index";
    }
    return( elems[index] );
  } // end of getElem()
private:
  int *elems;
  size_t numElems;
}; // end of class IntArray



// member functions can also be declared outside the class:

IntArray::IntArray() {
  cout << "in constructor\n";
  numElems = 0;
  elems = 0;
} // end of IntArray constructor


IntArray::~IntArray() {
  cout << "in destructor\n";
  free( elems );
  numElems = 0;
} // end of IntArray desctructor


void IntArray::setSize( size_t value ) {
  if ( elems != 0 ) {
    free( elems );
  }
  numElems = value;
  elems = (int *)malloc( value * sizeof( int ));
} // end of IntArray::setSize()


size_t IntArray::getSize() {
  return( numElems );
} // end of IntArray::getSize()


void IntArray::setElem( size_t index, int value ) {
  if (( index < -0 ) || ( index >= numElems )) {
    cerr << "bad index";
  }
  elems[index] = value;
} // end of IntArray::setElem()






int main() {
  IntArray powersOf2;
  powersOf2.setSize( 8 );
  powersOf2.setElem( 0, 1 );
  for ( int i=1; i<powersOf2.getSize(); i++ ) {
    powersOf2.setElem( i, 2*powersOf2.getElem( i-1 ));
  }
  cout << "here are the elements:\n";
  for ( int i=0; i<powersOf2.getSize(); i++ ) {
    cout << "i=" << i << " powerOf2=" << powersOf2.getElem( i ) << "\n";
  }
} // end of main()