/*
Example programs from the book Scientific and Engineering Programming
in C++: An Introduction with Advanced Techniques and Examples,
Addison-Wesley, 1994.
 
                 (c) COPYRIGHT INTERNATIONAL BUSINESS MACHINES
                 CORPORATION 1994.  ALL RIGHTS RESERVED.

See README file for further details.
*/
// Solution to exercise extending SimpleArray<T> by adding const members

template<class T>
SimpleArray<T>::SimpleArray(int n) {
    num_elts = n;
    ptr_to_data = new T[n];
}

template<class T>
SimpleArray<T>::SimpleArray() {
    num_elts = 0;
    ptr_to_data = 0;
}

template<class T>
SimpleArray<T>::SimpleArray(const SimpleArray<T>& a) {
    num_elts = a.num_elts;
    ptr_to_data = new T[num_elts];
    copy(a); // Copy a's elements
}

template<class T>
void SimpleArray<T>::copy(const SimpleArray<T>& a) {
    // Copy a's elements into the elements of *this
    T* p = ptr_to_data + num_elts;
    T* q = a.ptr_to_data + num_elts;
    while (p > ptr_to_data) *--p = *--q;
}

template<class T>
SimpleArray<T>::~SimpleArray() {
    delete [] ptr_to_data;
}

template<class T>
T& SimpleArray<T>::operator[](int i) {
    return ptr_to_data[i];
}

template<class T>
const T& SimpleArray<T>::operator[](int i) const {
    return ptr_to_data[i];
}

template<class T>
int SimpleArray<T>::numElts() const {
    return num_elts;
}

template<class T>
SimpleArray<T>& SimpleArray<T>::operator=(const SimpleArray<T>& rhs) {
    if ( ptr_to_data != rhs.ptr_to_data ) {
        setSize( rhs.num_elts );
        copy(rhs);
    }
    return *this;
}

template<class T>
void SimpleArray<T>::setSize(int n) {
    if (n != num_elts) {

        delete [] ptr_to_data;    // Delete old elements,
        num_elts = n;             // set new count,
        ptr_to_data = new T[n];   // and allocate new elements

    }
}

template<class T>
SimpleArray<T>& SimpleArray<T>::operator=(const T& rhs) {
    T* p = ptr_to_data + num_elts;
    while (p > ptr_to_data) *--p = rhs;
    return *this;
}