// An implementation of dynamically allocated strings.

#include <iostream.h>
#include <stdlib.h>
#include <string.h>

const int max_len = 255;

class string {
public:
   string() { len = 255; s = new char[255]; }        // constructor, inline
   string(int n) { s = new char[n + 1]; len = n; }   // constructor, inline
   string(const char* p);                            // constructor
   //
   // Because we do not want to deallocate the space
   // that is created by operator+(), we do not use the
   // destructor in this program.  Later, after we learn
   // how to overload the = operator, we will be able to
   // use it without difficulty.  To see what the effects
   // are, experiment by first running this program
   // without the destructor and then with it.
   //
   // ~string() { delete []s; }                      // destructor, inline
   //
   void   assign(const char* t) { strcpy(s, t); len = strlen(t); } 
   int    length() { return len; }
   void   print() { cout << s << "\nLength: " << len << "\n\n"; }

   friend string operator+(const string& a, const string& b);

private:
   char*   s;
   int     len;
};

int main()
{
   string  a, b(10), c("I came by horse.");

   cout << "\n";
   a.assign("By horse?");
   b.assign("Yes, by horse.");
   a = c + "  " + a;
   c = a + "  " + b;
   a.print();
   b.print();
   c.print();
   return 0;
}


string::string(const char* p) 
{ 
   len = strlen(p); 
   s = new char[len + 1]; 
   strcpy(s, p); 
} 

string operator+(const string& a, const string& b)                // overload +
{
   string tmp(a.len + b.len - 1);

   tmp.assign(a.s);
   if (tmp.len < max_len)
      strcat(tmp.s, b.s);
   else {
      cerr << "\nMax length exceeded - bye!\n\n";
      exit(1);
   }
   return tmp;
}