Ever consider making use of a primitive int or long as a bit array in Java ? An int, for example, would provide a capacity of 32 bits. But how would we go about setting and testing the nth bit efficiently ?

Possible solutions:

(Don't peek if you want to give it a try!)

    int setBitOn(int in, int pos) { return in | 1 << pos; }
    int setBitOff(int in, int pos) { return in & (-1 ^ (1 << pos)); }
    boolean isBitOn(int in, int pos) { return (in & (1 << pos)) != 0; }
    boolean isBitOff(int in, int pos) { return (in & (1 << pos)) == 0; }

Similarly for long,

    long setBitOn(long in, int pos) { return in | 1L << pos; }
    long setBitOff(long in, int pos) { return in & (-1L ^ (1L << pos)); }
    boolean isBitOn(long in, int pos) { return (in & (1L << pos)) != 0; }
    boolean isBitOff(long in, int pos) { return (in & (1L << pos)) == 0; }

Any faster, better or simpler way to do this ?