Using structs and unions to bitwise slice a builtin type

bit_wrangling.cpp

#include <iostream>
using namespace std;
//Custom slicing type
struct Bar {
	unsigned fn : 4; //first nibble
	unsigned sn : 4; //second nibble
};
//Representation
union Foo {
	short a;
	Bar b;
};

Foo * bat = new Foo;
bat->a = 30;
cout << "Orginal number: "bat->a << endl;
cout << "First nibble: " << bat->b.fn << endl;
cout << "Second nibble: " << bat->b.sn << endl;

int result = (bat->b.sn)<<4;
result += (bat->b.fn);
cout << "Putting them back together: " << result << endl;