bitsets

The STLs Bitsets are a great way to get flexible and expandable masking and flag logic without using using uints. They print nicely, mask correctly and are very readable compared to inline masking logic.

//complie with g++
#include <iostream>
#include <bitset>

using namespace std;

int main()
{
    const int count=50;
    bitset<count> bits;
    uint32_t      mask;

    bits = 0;
    mask = 0;

    cout << "All off" << endl;
    cout << bits << endl;
    cout << hex << mask << endl;

    //setting
    for(int i=0; i<count; i+=3)
    {
        bits[i] = true;        
        mask |= 1<<i;
    }

    cout << "Every 3rd on" << endl;
    cout << bits << endl;
    cout << hex << mask << endl;

    //masking test
    cout << "Self invert with ^" << endl;
    cout << (bits ^ bits) << endl;
    cout << hex << (mask ^ mask) << endl;

    cout << "Self mask with &" << endl;
    cout << (bits & bits) << endl;
    cout << hex << (mask & mask) << endl;

    //turn on all
    bits = 0; bits.flip();
    mask = -1;

    cout << "All on" << endl;
    cout << bits << endl;
    cout << hex << mask << endl;

    bits = -1; bits.flip();

    cout << "when bits are: " << bits << endl;
    cout << "check any on:  " << (bits != 0) << endl;
    cout << "check any off: " << (~bits != 0) << endl;

    bits = 0;

    cout << "when bits are: " << bits << endl;
    cout << "check any on:  " << (bits != 0) << endl;
    cout << "check any off: " << (~bits != 0) << endl;

    bits.flip();

    cout << "when bits are: " << bits << endl;
    cout << "check any on:  " << (bits != 0) << endl;
    cout << "check any off: " << (~bits != 0) << endl;

    return 0;
}

This outputs the following

All off
00000000000000000000000000000000000000000000000000
0
Every 3rd on
01001001001001001001001001001001001001001001001001
4925b6db
Self invert with ^
00000000000000000000000000000000000000000000000000
0
Self mask with &
01001001001001001001001001001001001001001001001001
4925b6db
All on
11111111111111111111111111111111111111111111111111
ffffffff
when bits are: 11111111111111111100000000000000000000000000000000
check any on:  1
check any off: 1
when bits are: 00000000000000000000000000000000000000000000000000
check any on:  0
check any off: 1
when bits are: 11111111111111111111111111111111111111111111111111
check any on:  1
check any off: 0