Method push_back

Exercises/NoModules/Chapter 17/Soln17_01/Array.h:85–94

// then the original Array<> remains untouched.
template <typename T>
void Array<T>::push_back(const T& newElement)
{
  Array<T> copy{ m_size + 1 };        // Copy...
  for (size_t i {}; i < m_size; ++i)
    copy[i] = m_elements[i];

  copy[m_size] = newElement;          // ... modify ...

  swap(copy);                         // ... and swap!  (noexcept)
}

// Swap member function template
template <typename T>