Packing is dependent on the order of things

gistfile1.cpp

#include <iostream>
#include <boost/integer.hpp>

typedef uint32_t NodeID;

struct EdgeData1 {
unsigned id:31;
bool shortcut:1;
int distance:30;
bool forward:1;
bool backward:1;
};

struct EdgeData2 {
unsigned id:31;
int distance:30;
bool shortcut:1;
bool forward:1;
bool backward:1;
};


int main(int argc, char * argv[]) {
  std::cout << "size: " << sizeof(EdgeData1) << std::endl;
	std::cout << "size: " << sizeof(EdgeData2) << std::endl;
	return 0;
}