[kstenerud]

Or if you only wanted to iterate halfway:

    unsigned int x = 0;

    while (x < ~x) {
        calc(x++);
    }

Or going down:

    unsigned int x = ~0;

    while (x > ~x) {
        calc(x--);
    }

[NoZebra120vClip]

By "halfway", did you mean "off by one"?

[kstenerud]

no