#ifndef _string_h
#define _string_h
#include <iostream.h>
#include <bool.h>
//
//  string class -- a subset of the standard C++ string class
//                  as defined in the draft ANSI document as:
//
//                  typedef basic_string<char> string;
//
//  This is a proper subset. All functions are part of the draft standard
//
//  6/26/95 Mike Clancy, Stu Hirshfield, Chris Nevison,
//          Owen Astrachan, Barbara Boucher Owens,
//
//======================================================================
//  Changes made by Rick Mercer on 25-Sep-1995 (remove 1..12 later)
//
//  1.  renamed s parameters to str (see standard)
//
//  2.  Changed    // assign s     to:   // assign str to this object
//
//  3.  Renamed s and t to lhs and rhs (see standard)
//
//  4.  After private: Changed   // mind your own business
//                          to:  // implementation dependent
//
//  5.  Moved these functions out of the class dec. Do we need them?
//      int    rfind(const string & s) const;  // as find, from right
//      int    rfind(char ch)          const;  // as find, from right
//
//  6.  Changed wording from      // concatenate string
//                        to      // append str to this object
//
//  7.  Added these two includes
//      #include <iostream.h>
//      #include <bool.h>
//
//  8.  Added the size and empty member functions
//
//  9. Added       string(const char * s);
//
// 10. Added       string & operator = (const char * s);
//
// 11. Changed mutator to modifiers
//
//  12. Addded  //----- for readability in string-d.cpp
//======================================================================
//
//

class string
{
public:

  //-----constructors

  string();                                  // default constructor, ""
  string(const char * s);                    // initializer: string("chars")
  string(const string & str);                // copy constructor

  //-----assignment

  string & operator = (const string & str);  // assign str to this object
  string & operator = (const char * s);      // assign s to this object
  string & operator = (char ch);             // assign ch to this object

  //-----accessors
															 // RETURN:
  int    length()                 const;     // number of chars
  bool   empty()                  const;     // size() == 0
  char   operator[int k]          const;     // k-th char (copy)  
  int    find(const string & str) const;     // index of str's start
  int    find(char ch)            const;     // index of first ch
  string substr(int pos, int len) const;     // len chars starting at pos

  //-----modifiers

  char &   operator[int k];                  // return k-th char reference
  string & operator += (const string & str); // append str to this object
  string & operator += (char ch);            // append char to this object

private:
  // implementation dependent

};                                            // end class string


// The following free (non-member) functions are part of the string module:

//-----relational operators

bool operator == (const string & lhs, const string & rhs);
bool operator != (const string & lhs, const string & rhs);
bool operator <  (const string & lhs, const string & rhs);
bool operator <= (const string & lhs, const string & rhs);
bool operator >  (const string & lhs, const string & rhs);
bool operator >= (const string & lhs, const string & rhs);

//-----stream I/O functions

ostream & operator << (ostream & os, const string & str);
istream & operator >> (istream & os, const string & str);
istream & getline(istream & is, string & str);

//-----concatenation operator +

string operator + (const string & lhs, const string & rhs);
string operator + (char ch, const string & str);
string operator + (const string & str, char ch);

#endif              // _string_h not defined