#include <iostream>
#include <string>
#include <algorithm>		// has copy()
#include <assert.h>		// has assert()

class foo {
public:
  // constructor and destructor
  foo (const unsigned int sz) {
    size = sz;
    if (size == 0) size += 1;
    array = new string[size];
  }
  ~foo(void) { delete [] array; }

  // copying functions
  foo(const foo & f) {
    copier(f);
    return;
  }
  foo& operator=(const foo & f) {
    if (this != &f) {
      delete [] array;
      copier(f);
    }
    return *this;
  }
  
  // element access
  string& operator[](unsigned int i) {
    assert(i < size);
    return array[i];
  }
  const string& operator[](unsigned int i) const {
    assert(i < size);
    return array[i];
  }

  // output
  friend ostream& operator<<(ostream& out, const foo & f) {
    for (unsigned int i = 0; i < f.size; i += 1)
      out << f.array[i] << endl;
    return out;
  }

private:
  unsigned int size;
  string * array;
  
  void copier(const foo & f) {
    size = f.size;
    array = new string[size];
    copy(f.array, f.array + size, array);
    return;
  }
};


int main(void) {
  foo f(4);
  foo g(4);
  f[0] = f[2] = "hello";
  f[1] = (f[3] = "world");
  g = f;
  cout << "f:\n" << f;
  cout << "g:\n" << g;
  return EXIT_SUCCESS;
}