bitfield_experiment.cpp

#include <iostream>

#pragma pack(0)

// a 4-bit  bitfield
struct word_t {
	unsigned int val : 4;
};

// 8-bits
struct octet {
	bool b0 : 1, b1 : 1, b2 : 1, b3 : 1,
		 b4 : 1, b5 : 1, b6 : 1, b7 : 1;	
};

// prints some memory in binary
void printBits(char* bytes, size_t len){
	for (; len > 0; len--, bytes++) {
		std::cout	<<((octet*) bytes)-> b0 <<((octet*) bytes)-> b1
					<<((octet*) bytes)-> b2 <<((octet*) bytes)-> b3
					<<((octet*) bytes)-> b4 <<((octet*) bytes)-> b5
					<<((octet*) bytes)-> b6 <<((octet*) bytes)-> b7
					<<" = " <<((word_t*) bytes)->val <<"\t:: " 
					<<(void*) bytes <<'\n';
	}

}

int main(){

	word_t wrds[5] = { { 15 }, { 15 } , { 0 }, { 0}, { 5 } };
	std::cout <<sizeof(wrds) <<'\n';
	printBits((char*)wrds, 5);

/*
	word_t a;
	a.val = 0;
	std::cout <<sizeof(a) <<'\n' <<sizeof(word_t) <<'\n';
	for (int i = 0; i < 20; i++)
		std::cout <<a.val++ <<'\n';
*/


}