//  class_simple_string.h  (c) 1998-2001 Kari Laitinen

/*  To make Borland C++ 5.5.1 compiler accept this program,
    the argument of function operator= must be of type
    const Simple_string&. That is an error in the compiler
    because some other compilers compile the function without
    the const declaration. The keyword const here does not
    affect the behavior of the program. This program is 
    presented in the book without the const declaration.  */

#ifndef  CLASS_SIMPLE_STRING_H   // prohibiting multiple inclusions
#define  CLASS_SIMPLE_STRING_H

class  Simple_string
{
protected:
   char  characters_of_this_string[ 100 ] ;
   int   number_of_characters_in_this_string ;

public:
   Simple_string() ;
   Simple_string( char given_traditional_string[] ) ;
   Simple_string( Simple_string&  given_simple_string ) ;

   Simple_string   operator+ ( Simple_string& string_to_append ) ;
   Simple_string&  operator= ( const Simple_string& string_to_copy ) ;

   char&  operator[] ( int  string_index ) ;

   friend  ostream& operator<< ( ostream&        output_stream,
                                 Simple_string&  string_to_output ) ;
} ;

Simple_string::Simple_string()
{
   number_of_characters_in_this_string  =  0 ;
}

Simple_string::Simple_string( char  given_traditional_string[] )
{
   int character_index  =  0 ;

   while ( given_traditional_string[ character_index ]  !=  0 )
   {
      characters_of_this_string[ character_index ]  =
                 given_traditional_string[ character_index ] ;

      character_index  ++ ;
   }

   number_of_characters_in_this_string  =  character_index ;
}

Simple_string::Simple_string( Simple_string& given_simple_string )
{
   number_of_characters_in_this_string  =
       given_simple_string.number_of_characters_in_this_string ;

   for ( int character_index  =  0 ;
             character_index  <  number_of_characters_in_this_string ;
             character_index  ++ ) 
   {
      characters_of_this_string[ character_index ]  =
       given_simple_string.characters_of_this_string[ character_index ] ;
   }
}

Simple_string
Simple_string::operator+ ( Simple_string&  string_to_append )
{
   Simple_string  sum_of_strings( *this ) ;

   //  sum_of_strings  is  now a copy of "this" string.
   //  All we have to do is to copy the characters of
   //  string_to_append to the end of sum_of_strings.

   int character_index  =  0 ;

   while ( character_index  <  
                string_to_append.number_of_characters_in_this_string )
   {
      sum_of_strings.characters_of_this_string[
          sum_of_strings.number_of_characters_in_this_string +
          character_index ] =
        string_to_append.characters_of_this_string[ character_index ] ;

      character_index  ++  ;
   }

   sum_of_strings.number_of_characters_in_this_string  =
         sum_of_strings.number_of_characters_in_this_string +
         string_to_append.number_of_characters_in_this_string ;

   return  sum_of_strings ;
}


Simple_string&
Simple_string::operator= ( const Simple_string&  string_to_copy )
{
   if ( this  !=  &string_to_copy )
   {
      number_of_characters_in_this_string  =
              string_to_copy.number_of_characters_in_this_string ;

      for ( int character_index  =  0 ;
                character_index  <  number_of_characters_in_this_string ;
                character_index  ++ ) 
      {
         characters_of_this_string[ character_index ]  =
           string_to_copy.characters_of_this_string[ character_index ] ;
      }
   }

   return  *this  ;
}


ostream& operator<< ( ostream&        output_stream,
                      Simple_string&  string_to_output )
{
   int character_index  =  0 ;

   while ( character_index  <  string_to_output.
                                number_of_characters_in_this_string )
   {
      output_stream  <<  
        string_to_output.characters_of_this_string[ character_index ] ;

      character_index   ++  ;
   }         

   return  output_stream ;
}


#endif  // end of include guard