// Prog: vector.h
// definition of the class ifmp::vector

namespace ifmp {
  class vector {
  public:
    typedef int*       iterator;
    typedef const int* const_iterator;
   
    // default constructor
    // POST: *this is an empty vector
    vector ();
    
    // POST: *this is a vector of size s
    vector (const unsigned int s);
    
    // POST: *this is a vector of size s, elements initialized with val
    vector (const unsigned int s, const int& val); 
    
    // copy constructor
    vector (const vector& v);
    
    // assignment operator
    vector& operator= (const vector& v);
    
    // destructor
    ~vector ();
    
    // POST: *this was emptied
    void clear ();
    
    // POST: returns the size of the vector
    unsigned int size () const;
    
    // POST: returns the capacity of the vector
    unsigned int capacity () const;
    
    // POST: element with value val is appended to *this,
    //       capacity of *this was increased if necessary
    void push_back (const int& val);
    
    // POST: returns an iterator pointing to the first element
    iterator begin ();
    const_iterator begin () const;
    
    // POST: returns a past-the-end iterator
    iterator end ();
    const_iterator end () const;
    
    // PRE:  n < size()
    // POST: returns a reference to the n-th element
    int& operator[] (const unsigned int n);

    // PRE:  n < size()
    // POST: returns a const reference to the n-th element
    const int& operator[] (const unsigned int n) const;

  private:
    iterator begin_;
    iterator end_;
    iterator end_of_memory_;
    
    // PRE: [begin, end) is a valid range, [to, to + end-begin) points to
    //      allocated memory and is not overlapping with [begin, end)
    // POST: elements in [begin, end) are copied to the range 
    //       [to, to + end-begin), returns an iterator pointing to the
    //       end of the destination range
    iterator copy (iterator begin, iterator end, iterator to);
    
    // POST: *this has twice as much capacity as before or at least 1
    void increase_capacity ();

    // PRE: c >= size()
    // POST: *this has capacity at least c
    void increase_capacity (const unsigned int c);
  };
  
} // end namespace