#if ! defined(_CREATURE_H_)
#define _CREATURE_H_

#include <iostream.h>

#define MAXNAME 20

class creature {
private:
    static int count;
    char name[MAXNAME];
public:
    const int id;
    creature(char const * nm);
    ~creature(void);
    creature(creature const & src);
    creature marry(creature const & b);
friend ostream & operator <<(ostream & os, creature const & x);
};

#endif

//#include "creature.h"
#include <string.h>

int creature::count(0);

creature::creature(char const *nm) : id(++count)
{
    strncpy(name, nm, sizeof(name)-1);
    cout << *this << " is born\n";
}

creature::~creature(void)
{
    cout << *this << " is gone.\n";
}

creature::creature(creature const & src) : id(++count)
{
    strncpy(name, src.name, sizeof(name)-1);
    cout << *this << " is a copy of " << src << "\n";
}

ostream & operator <<(ostream & os, creature const & x)
{
    return os << x.name << '(' << x.id << ')';
}

#include <stdlib.h>

creature creature::marry(creature const & b)
{
    int i;
    char tmp[MAXNAME];

    for (i=0; name[i] && b.name[i]; ++i)
	tmp[i] = random() > RAND_MAX/2 ? name[i] : b.name[i];
    tmp[i] = '\0';
    return creature(tmp);
}


#if defined(TEST)

#include <assert.h>

int main(int argc, char *argv[])
{
    assert(3 <= argc >= 3 && 4 >= argc);
    if (4 <= argc) srandom(atoi(argv[3]));

    creature lambda(argv[1]);
    creature alpha(argv[2]), beta(lambda);

    cout << alpha.marry(beta) << " rules the world!\n";
}

#endif

/*
a.out "windows" " intel" 30
windows(1) is born
 intel(2) is born
windows(3) is a copy of windows(1)
wintel(4) is born
wintel(4) rules the world!
wintel(4) is gone.
windows(3) is gone.
 intel(2) is gone.
windows(1) is gone.
*/

/*
Exercises:
1. Separate the code into 3 files, write a makefile, and make.
2. What if '&' is removed from the parameter to the copy constructor?
3. What if '&' is removed from the parameter to creature::marry()?
4. What if creature::marry() takes a pointer as a parameter?
5. What if a 4-th creature delta is copied from the return value of
   alpha.marry(beta), and we use delta in the cout statement instead?
6. Modify creature::marry() so that it produces an offsping whose
   name is of the same length as the longer of the two parents.
*/