std.intrinsic and structs

[Jaheera]

I had some questions about the std.intrinsic functions:

Is it possible to do bt, bts and btr operations on ulongs as is already 
possible on uints?

Why do the intrinsic operations not return bool, instead of 0 and -1?


I also have a question about structs.

I want to do this, but this obviously doesn't work:

struct foo(int var)
{
    int[var] x;
}

struct bar
{
    foo[4] zeb(10);
}

Thanks.