StaticBitArray.opApply

static bool[] ba = [1,0,1];
auto a = StaticBitArray!3(ba);
size_t i;
foreach (immutable b; a[]) // TODO is `opSlice` the right thing?
{
    switch (i)
    {
    case 0: assert(b == true); break;
    case 1: assert(b == false); break;
    case 2: assert(b == true); break;
    default: assert(0);
    }
    i++;
}
foreach (j, b; a)       // TODO is `opSlice` the right thing?
{
    switch (j)
    {
    case 0: assert(b == true); break;
    case 1: assert(b == false); break;
    case 2: assert(b == true); break;
    default: assert(0);
    }
}