// bitbucket.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>

using namespace std;
const int SZ = 4;

class BitBucket {
	unsigned char data[SZ]; 
	int cnt;
public :
	BitBucket(); 

	// friend functions (of a class) are able to access private data
	// THIS IS NOT A MEMBER FUNCTION!!!
	friend ostream& operator << (ostream &, BitBucket &);
	friend int operator << (BitBucket &, const int);
	friend int operator >> (BitBucket &, const int n);
	BitBucket& operator + (BitBucket &);
};


BitBucket& BitBucket::operator+ (BitBucket &b) {
		

	return *this;
}

BitBucket::BitBucket() {
	for (int i=0; i < SZ; i++) 
		data[i] = 0xcc; // just put some data

	cnt = 0;
}

int operator >> (BitBucket &b, const int n) {
	unsigned char o = 0, r; // o : overflow, r : current remaining
	int i = 0;				// iterate over all elements of data[]
							// starting from the 'MOST' significant
							// which in this example happens to be
							// the FIRST element of the data[] array

	do  {
		r = b.data[i];
		r <<= sizeof (unsigned char) * 8  - n;
		b.data[i] >>= n;
		b.data[i] |= o;
		o = r;
	} while (++i < SZ);
	
	b.cnt -= n;
	if (b.cnt < 0)
		b.cnt = 0;

	return o;
}

int operator << (BitBucket &b, const int n) {
	unsigned char o = 0, r; // o : overflow, r : current remaining
	int i = SZ - 1;			// iterate over all elements of data[]
							// starting from the 'LEAST' significant
							// which in this example happens to be
							// the LAST element of the data[] array
	do  {
		r = b.data[i];
		r >>= sizeof(unsigned char)*8 - n;	// size of data structure * bits - number of bits to move
		b.data[i] <<= n;
		b.data[i] |= o;
		o = r;
	} while (i--);
	
	b.cnt = b.cnt+n;

	if (b.cnt > sizeof(unsigned char) * 8 * SZ ) 
		b.cnt = sizeof(unsigned char) * 8 * SZ ;

	return o;
}

ostream& operator << ( ostream &ostr, BitBucket &b) {
	cout << endl;
	for (int j=0; j < SZ; j++) {
		for (int i=sizeof(unsigned char) * 8 - 1; i>=0; i--) {
			if (b.data[j] & ( 1 << i ) ) 
				ostr << 1;
			else 
				ostr << 0;
		}

		cout << ' ';
	}

	cout << endl;

	return ostr;		// return stream to be available for next operation
}

int operator +(const int a, BitBucket &b) {
	return 10;

}

int main()
{
	BitBucket b;
	int a = (6 + b);	// just a dummy showcase

	((cout << "content before shift") << b);
	b << 5;
	((cout << "content after shift left") << b);
	b >> 5;
	((cout << "content after shift right") << b);

	return 0;
}